Konstantin Litvineko

Dr Konstantin (Constantine) Litvinenko


Research Fellow and Teaching Fellow in Physics
BSc, MSc, PhD
+44 (0)1483 689867
19 ATI 02

Academic and research departments

Advanced Technology Institute.

My publications

Publications

Pavlov S. G., Hübers H. -W. ., Shuman V. B., Portsel L. M., Lodygin A. N., LI JUERONG, LE HUY NGUYEN, Fisher A., Astrov A., Abrosimov N. V., Pidgeon C. R., Zeng Zaiping, Niquet Y. -M., MURDIN BENEDICT NEIL, Engelkamp H., LITVINENKO KONSTANTIN, CLOWES STEVEN K (2018)Radii of Rydberg states of isolated silicon donors, In: Physical Review B98085423 American Physical Society
We have performed a high field magneto-absorption spectroscopy on silicon doped with a variety of single and double donor species. The magnetic field provides access to an experimental magnetic length, and the quadratic Zeeman effect in particular may~be used to extract the wavefunction radius without reliance on previously determined effective mass parameters. We were therefore able to determine the limits of validity for the standard one-band anisotropic effective mass model. We also provide improved parameters and use them for an independent check on the accuracy of effective mass theory. Finally, we show that the optically accessible excited state wavefunctions have the attractive property that interactions with neighbours are far more forgiving of position errors than (say) the ground state.
Pidgeon C, Saeedi K, van Loon M, Stavrias Nikolaos, LE HUY NGUYEN, Litvinenko Konstantin, Greenland P, Redlich B, Aeppli G, Murdin Benedict (2018)Giant multiphoton absorption for THz resonances in silicon hydrogenic donors, In: Nature Photonics12pp. 179-184 Nature Publishing Group
The absorption of multiple photons when there is no resonant intermediate state is a well-known nonlinear process in atomic vapours, dyes and semiconductors. The N-photon absorption (NPA) rate for donors in semiconductors scales proportionally from hydrogenic atoms in vacuum with the dielectric constant and inversely with the effective mass, factors that carry exponents 6N and 4N, respectively, suggesting that extremely large enhancements are possible. We observed 1PA, 2PA and 3PA in Si:P with a terahertz free-electron laser. The 2PA coefficient for 1s–2s at 4.25 THz was 400,000,000 GM (=4 × 10−42 cm4 s), many orders of magnitude larger than is available in other systems. Such high cross-sections allow us to enter a regime where the NPA cross-section exceeds that of 1PA—that is, when the intensity approaches the binding energy per Bohr radius squared divided by the uncertainty time (only 3.84 MW cm−2 in silicon)—and will enable new kinds of terahertz quantum control.
This thesis is concerned with the generation of terahertz (THz) light in the frequency range of 5–15 THz. This range is difficult to produce at high intensities, and no high-power table-top sources exist for it. The reasons for the interest in this frequency range are broad, and include communications, chemical and biomedical spectroscopy, etc. Different applications require highly specific technological characteristics, such as room temperature operation or very high stability, and satisfying all possible requirements in one generation mechanism is difficult. In this study, we sought to develop a solution to the problem of optical pumping of donor impurities in silicon, to control the orbit and spin of the donor electron in quantum computer gates. It is obvious that great advantages would be obtained if this control were possible with a bench-top source, and this is the key to enabling such high efficiency control to spread to the wider community of physicists and engineers working on spin qubits. To achieve this purpose, we explore the possibility of use a cheap material like single doped silicon and germanium to triple THz radiation from 1.7 to 5 THz (which is available from Quantum Cascade Laser diodes). The presence of the dopants modifies substantially the optical properties of the semiconductors, generating large nonlinear coefficients at THz frequencies. Samples of bismuth doped silicon and phosphorus, arsenic and antimony doped germanium has been characterised using frequency-domain and time-domain spectroscopy, and finally the optical nonlinear coefficient of Si:Bi has been measure by a Four Wave Mixing (FWM) experiment. We have found that the nonlinear susceptibility $____chi^{(3)}$ of Si:Bi at resonance is the highest ever reported for a bulk material.
Litvinenko Konstantin, Greenland PT, Redlich B, Pidgeon CR, Aeppli G, Murdin Benedict (2016)Weak probe readout of coherent impurity orbital superpositions in silicon, In: Physical Review B - Condensed Matter and Materials Physics94(23)235207 American Physical Society
Pump-probe spectroscopy is the most common time-resolved technique for investigation of electronic dynamics, and the results provide the incoherent population decay time T1. Here we use a modified pump-probe experiment to investigate coherent dynamics, and we demonstrate this with a measurement of the inhomogeneous dephasing time T2* for phosphorus impurities in silicon. The pulse sequence produces the same information as previous coherent all-optical (photon-echo-based) techniques but is simpler. The probe signal strength is first order in pulse area but its effect on the target state is only second order, meaning that it does not demolish the quantum information. We propose simple extensions to the technique to measure the homogeneous dephasing time T2, or to perform tomography of the target qubit.
Litvinenko K. L., Nikzad L., Allam J., Murdin B. N., Pidgeon C. R., Harris J. J., Zhang T., Cohen L. F. (2007)Spin lifetime in high quality InSb epitaxial layers grown on GaAs, In: Journal of Applied Physics083105(2007)

The spin relaxation in undoped InSb films grown on GaAs has been investigated in the temperature range from 77 to 290 K. Two distinct lifetime values have been extracted, 1 and 2.5 ps, dependent on film thickness. Comparison of this data with a multilayer transport analysis of the films suggests that the longer time (~2.5 ps at 290 K) is associated with the central intrinsic region of the film, while the shorter time (~1 ps) is related to the highly dislocated accumulation region at the film-substrate interface. Whereas previous work on InAs films grown on GaAs showed that the native surface defect resulted in an additional charge accumulation layer with high conductivity but very short spin lifetime, in InSb layers the surface states introduce a depletion region. We infer that InSb could be a more attractive candidate for spintronic applications than InAs.

Zhang T, Clowes S K, Branford W R, Harris J, Cohen L F, Pidgeon C R, Murdin B N, Litvinenko K, Allam J, Bird M, Morrison K (2005)Temperature and Doping Dependence of Spin Relaxation in n-InAs, In: Physical Review B72(8)

We have used time-resolved spectroscopy to measure the relaxation of spin polarizations in the narrow gap semiconductor material n-InAs as a function of temperature, doping, and pump wavelength. The results are consistent with the D'Yakonov-Perel mechanism for temperatures between 77 and 300 K. However, the data suggest that electron-electron scattering should be taken into account in determining the dependence of the spin lifetime on the carrier concentration in the range 5.2x10(16)-8.8x10(17) cm(-3). For a sample with doping of 1.22x10(17) cm(-3) the spin lifetime was 24 ps at room temperature. By applying a magnetic field in the sample plane we also observed coherent precession of the spins in the time domain, with a g factor g(*)=-13, also at room temperature.

Jefferson J. H., Miller A., Cohen L. F., Murzyn P., Pidgeon C. R., Phillips P. J., Merrick M., Litvinenko K. L., Ashley T., Allam J., Murdin B. N. (2005)Erratum: "Suppression of D'yakonov-Perel spin relaxation in InAs and InSb by n-type doping at 300 K" [Appl. Phys. Lett. 83, 5220 (2003)], In: Applied Physics Letters129901(2005)
Murdin BN, Merrick M, Litvinenko K, Murzyn P, Phillips PJ, Pidgeon CR, Zhang T, Clowes SK, Cohen LF, Buckle P, Ashley T (2004)Spin lifetimes in narrow gap semiconductors measured with free-electron and solid-state lasers, In: Buckley DN, Chang PC, Fox PD, Chan WK, Shiojima K, (eds.), STATE-OF-THE-ART PROGRAM ON COMPOUND SEMICONDUCTORS XL (SOTAPOCS XL) AND NARROW BANDGAP OPTOELECTRONIC MATERIALS AND DEVICES II2004(2)pp. 253-258
Starukhin AN, Razbirin BS, Chugreev AV, Nelson DK, Grushko YS, Kolesnik SN, Hvam JM, Birkedal D, Litvinenko K, Spiegelberg C, Zeman J, Martinez G (1997)High-resolution spectroscopy of matrix-isolated fullerene molecules, In: JOURNAL OF LUMINESCENCE72-4pp. 457-458
Allam J, Sutton R, Sjjad M, Litvinenko K, Siddique S, Wang Z, Yang Q-H, Brwon T, Loh W (2010)Reaction, diffusion and dissociation of excitons on carbon nanotubes, In: OSA Technical Digest (CD)
We study exciton reactions on carbon nanotubes in the regime of many, few and one exciton per nanotube, and demonstrate classic 1-D reaction-diffusion behaviour. Dissociation occurs when exciton spacing is less than the exciton length.
Sajjad M, Wang Z, Siddique S, Sutton R, Litvinenko K, Mersch D, King A, Dalton A, Allam J (2009)Annihilation and anomalous trapping of excitons in carbon nanotubes
Litvinenko K, Birkedal D, Lyssenko VG, Hvam JM (1999)Exciton dynamics in GaAs/AlxGa1-xAs quantum wells, In: PHYSICAL REVIEW B59(15)pp. 10255-10260 AMER PHYSICAL SOC
Litvinenko KL, Nikzad L, Allam J, Murdin BN, Pidgeon CR, Harris JJ, Cohen LF (2007)Spin dynamics in narrow-gap semiconductor epitaxial layers, In: JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM20(6)pp. 461-465
Wang Z, Sajjad M, Siddique S, Sutton R, Litvinenko K, Mersch D, King A, Dalton A, Allam J (2009)Optical response of carbon nanotubes: exciton and plasmon contributions
Litvinenko K, Leontiadou M, Li J, Murdin B, Bowyer E, Clowes S, Pidgeon CR (2011)Manipulation of spin dynamics in semiconductor structures by orientation of small external magnetic field, In: AIP Conference Proceedings1399pp. 657-658
Electron spin relaxation times have been measured in InSb and InAs quantum wells and epi-layers in a moderate (<4T) external magnetic field by means of time-resolved optical orientation using circularly polarised light. A strong and opposite field dependence of the spin lifetime was observed for longitudinal (Faraday) and transverse (Voigt) configuration. In the Faraday configuration the spin lifetime increases because the DP dephasing process is suppressed. At the high field limit the EY relaxation process dominates, enabling its direct determination. Conversely, in the Voigt configuration an additional efficient spin dephasing mechanism dominates and shortens the electron spin lifetime considerably with B-2. We demonstrate that for narrow gap semiconductors simply changing the direction of the magnetic field of 1T can alter the electron spin lifetime by one order of magnitude.
Litvinenko KL, Murdin BN, Clowes SK, Nikzad L, Allam J, Pidgeon CR, Branford W, Cohen LF, Ashley T, Buckle L (2008)Density and well-width dependence of the spin relaxation in n-InSb/AlInSb quantum wells, In: Murdin BN, Clowes S, (eds.), NARROW GAP SEMICONDUCTORS 2007119pp. 19-21
Litvinenko Konstantin, Li Juerong, Stavrias N, Meaney A, Christianen P, Engelkamp H, Homewood Kevin, Pidgeon C, Murdin Benedict (2016)The Quadratic Zeeman effect used for state-radius determination in neutral donors and donor bound excitons in Si:P, In: Semiconductor Science and Technology31045007pp. 045007-045007 IOP
We have measured the near-infrared photoluminescence spectrum of phosphorus doped silicon (Si: P) and extracted the donor-bound exciton (D0X) energy at magnetic fields up to 28 T. At high field the Zeeman effect is strongly nonlinear because of the diamagnetic shift, also known as the quadratic Zeeman effect (QZE). The magnitude of the QZE is determined by the spatial extent of the wave-function. High field data allows us to extract values for the radius of the neutral donor (D0) ground state, and the light and heavy hole D0X states, all with more than an order of magnitude better precision than previous work. Good agreement was found between the experimental state radius and an effective mass model for D0. The D0X results are much more surprising, and the radius of the mJ=±3/2 heavy hole is found to be larger than that of the mJ=±1/2 light hole.
Davies G, Liaugaudas G, Vinh NQ, Litvinenko K (2010)Three phonon decay mode of the 1136-cm(-1) nu(3) vibration of oxygen in silicon, In: PHYSICAL REVIEW B81(3)ARTN 03320 AMER PHYSICAL SOC
Litvinenko K (2001)Radiationless relaxation in a synthetic analogue of the green fluorescent protein chromophore, In: The Journal of Physical Chemistry Part B: Condensed Matter, Materials, Surfaces, Interfaces and Biophysical American Chemical Society
The fluorescence and ultrafast ground-state recovery times of the isolated chromophore of the green fluorescent protein have been studied in basic alcohol solutions. The fluorescence quantum yield increases more than 103 times between 295 and 77 K. The major part of the increase occurs in the supercooled liquid range, and continues below the glass transition. The ground-state recovery at 295 K is essentially (95%) complete in under 5 ps, is nonexponential, and only weakly dependent on solvent viscosity. These results are inconsistent with a viscosity-controlled radiationless process involving large scale intramolecular reorganization. If intramolecular motion is involved it must be of small scale. Alternative mechanisms are discussed. A thermally activated radiationless decay process is consistent with the present data, but the mechanism is unclear. For either mechanism the high quantum yield in the intact protein must arise through protein−chromophore interactions which effectively suppress the radiationless channel.
Dignam M, Kohler K, Leo K, Litvinenko K, Loser F, Lyssenko VG, Sudzius M, Valusis G (1999)New features of spatial-temporal dynamics of Bloch oscillations, In: Asmontas S, Dargys A, (eds.), ULTRAFAST PHENOMENA IN SEMICONDUCTORS297-2pp. 11-16
Loh W, Allam J, Sutton R, Sajjad M, Litvinenko K, Wang Z, Siddique S, Yang Q-H, Brown T (2010)Exciton reaction on carbon nanotubes: role of spatial distribution
Pidgeon CR, Litvinenko KL, Nikzad L, Allam J, Cohen LF, Ashley T, Emeny M, Murdin BN (2008)Temperature dependence of the electron Lande g-factor in InSb, In: Murdin BN, Clowes S, (eds.), NARROW GAP SEMICONDUCTORS 2007119pp. 27-29
Huebers H-W, Pavlov SG, Lynch SA, Greenland T, Litvinenko KL, Murdin B, Redlich B, van der Meer AFG, Riemann H, Abrosimov NV, Becker P, Pohl H-J, Zhukavin RK, Shastin VN (2013)Isotope effect on the lifetime of the 2p(0) state in phosphorus-doped silicon, In: PHYSICAL REVIEW B88(3)ARTN 0pp. ?-? AMER PHYSICAL SOC
Litvinenko K, Kohler K, Leo K, Loser F, Lyssenko VG (1999)Nonharmonic Bloch oscillations in GaAs/AlGaAs superlattices, In: Asmontas S, Dargys A, (eds.), ULTRAFAST PHENOMENA IN SEMICONDUCTORS297-2pp. 17-20
Leontiadou MA, Litvinenko KL, Gilbertson AM, Pidgeon CR, Branford WR, Cohen LF, Fearn M, Ashley T, Emeny MT, Murdin BN, Clowes SK (2011)Experimental determination of the Rashba coefficient in InSb/InAlSb quantum wells at zero magnetic field and elevated temperatures, In: JOURNAL OF PHYSICS-CONDENSED MATTER23(3)ARTN 0pp. ?-? IOP PUBLISHING LTD
Murdin BN, Litvinenko K, Li J, Bowyer E, Pang M, Greenland PT, Villis B, Aeppli G, van der Meer AFG, Redlich B, Engelkamp H, Pidgeon CR (2015)Nano-orbitronics in silicon, In: Bigot JY, Hubner W, Rasing T, Chantrell R (eds.), ULTRAFAST MAGNETISM I159pp. 92-93 SPRINGER INT PUBLISHING AG
Litvinenko K. L., Nikzad L., Pidgeon C. R., Allam J., Cohen L. F., Ashley T., Emeny M., Zawadzki W., Murdin B. N. (2008)Temperature dependence of the electron Landé g factor in InSb and GaAs, In: Physical Review B77(033204)

We report Larmor precession in bulk InSb observed in the time domain from 77 to 300 K. The optically oriented polarization precesses coherently even at 300 K. The inferred Zeeman spin splitting is strongly nonparabolic, and the electron g factor (g*) is in good agreement with k·p theory (provided we take only the dilational contribution to the change in energy gap with temperature). We also show here that correct application of the 14-band k·p model agrees with apparently anomalous trends previously reported for GaAs and confirm that the most widely quoted formula for g* in GaAs is incomplete.

Li Juerong, Gilbertson AM, Litvinenko Konstantin, Cohen LF, Clowes Steven (2012)Transverse focusing of spin-polarized photocurrents, In: Physical Review B (Condensed Matter and Materials Physics)85(4)045431 American Physical Society
We measure transverse magnetically focused photocurrent signals in an InSb/InAlSb quantum well device. Using optical spin orientation by modulated circularly polarized light an electron spin-dependent signal is observed due to the spin-orbit interaction. Simulations of the focusing signal are performed using a classical billiard ball model, which includes both spin precession and a spin-dependent electron energy. The simulated data suggest that a signal dependent on the helicity of the incident light is expected for a Rashba parameter α > 0.1 eVÅ and that a splitting of the focusing signal is not expected to be observed in linear polarized photocurrent and purely electrical measurements.
Vinh NQ, Greenland PT, Litvinenko K, Redlich B, van der Meer AFG, Lynch SA, Warner M, Stoneham AM, Aeppli G, Paul DJ, Pidgeon CR, Murdin BN (2008)Silicon as a model ion trap: Time domain measurements of donor Rydberg states, In: PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA105(31)pp. 10649-10653 NATL ACAD SCIENCES
Abrosimov NV, Riemann H, Pavlov SG, Hübers HW, Murdin PG, Murdin BN, Li J, Pang ML, Bowyer ET, Litvinenko KL, Clowes SK, Engelkamp H, Pidgeon CR, Galbraith I (2013)Si:P as a laboratory analogue for hydrogen on high magnetic field white dwarf stars., In: Nat Commun4pp. 1469-? Nature Publishing Group
Laboratory spectroscopy of atomic hydrogen in a magnetic flux density of 10(5) T (1 gigagauss), the maximum observed on high-field magnetic white dwarfs, is impossible because practically available fields are about a thousand times less. In this regime, the cyclotron and binding energies become equal. Here we demonstrate Lyman series spectra for phosphorus impurities in silicon up to the equivalent field, which is scaled to 32.8 T by the effective mass and dielectric constant. The spectra reproduce the high-field theory for free hydrogen, with quadratic Zeeman splitting and strong mixing of spherical harmonics. They show the way for experiments on He and H(2) analogues, and for investigation of He(2), a bound molecule predicted under extreme field conditions.
Wright NM, Thomson DJ, Litvinenko KL, Headley WR, Smith AJ, Knights AP, Gardes FY, Mashanovich GZ, Gwilliam R, Reed GT (2008)Free carrier lifetime modification for silicon waveguide based devices, In: Proceedings of 5th IEEE International Conference on Group IV Photonicspp. 122-124
We investigate the effects of implanting silicon directly into a silicon waveguide to modify carrier lifetime. Experimental results show over 85% reduction in the carrier lifetime for only a small net increase in optical absorption.
Leontiadoa M, Clowes S, Litvinenko K, Pidgeon CR, Ashley T, Emeny M, Murdin B (2009)Variable g-factor spin relaxation in InSb in an external magnetic field
Allam J, Sutton R, Sajjad MT, Litvinenko K, Wang Z, Siddique S, Yang QH, Brown T, Loh W (2010)Reaction, diffusion and dissociation of excitons on carbon nanotubes, In: Optics InfoBase Conference Papers
Photoexcitation of carbon nanotubes generates excitons which decay by exciton-exciton annihilation at sufficient density. We examine this decay under conditions of one, few and many excitons per nanotube. A classic 1D reaction-diffusion behaviour is observed, with decay limited by diffusion for t>3ps and by reaction for t<3ps. At high densities the exciton population saturates, and by analysis of the rate equations we show that this is consistent with dissociation of excitons when their spacing is 1.3nm, close to the exciton length. © 2010 Optical Society of America.
Murdin BN, Abrosimov NV, Litvinenko KL, Pavlov SG, Huebers H-W, Pidgeon CR (2014)Photon assisted tunneling in pairs of silicon donors, In: PHYSICAL REVIEW B89(23)ARTN 2pp. ?-? AMER PHYSICAL SOC
Li J, Litvinenko KL, Clowes SK, Gilbertson AM, Cohen LF (2012)Observation of spin dependent photocoductivity in InSb quantum well nanowires, In: Applied Physics Letters101(15) AIP
We report on the electrical detection of spin dependent photoconductivity in 500 nm wide InSb quantum well nanowires using the optical orientation of electron spins. By applying weak magnetic fields (≈ 200 mT), we observe a spin filtering effect of classical origin caused by spin dependent back scattering of electrons from the sidewalls. Spin dependent features in the longitudinal photovoltage decay with temperature and disappears at characteristic energy (≈ 50 K) consistent with the theoretical spin splitting and the thermal level broadening. We show that the observed signal is due to the inversion asymmetry of the quantum well, with an additional Zeeman contribution. © 2012 American Institute of Physics.
Wright NM, Smith AJ, Litvinenko K, Gwilliam R, Mashanovich G, Reed GT (2010)Effects of annealing silicon ion irradiated rib waveguides with respect to free carrier lifetime, In: Proceedings of SPIE - The International Society for Optical Engineering7606
Saeedi K, Szech M, Dluhy P, Salvail JZ, Morse KJ, Riemann H, Abrosimov NV, Noetzel N, Litvinenko KL, Murdin BN, Thewalt MLW (2015)Optical pumping and readout of bismuth hyperfine states in silicon for atomic clock applications, In: SCIENTIFIC REPORTS5ARTN 1pp. ?-? NATURE PUBLISHING GROUP
Murzyn P, Pidgeon C R, Phillips P J, Merrick M, Litvinenko K L, Allam J, Murdin B N, Ashley T, Jefferson J H, Miller A, Cohen L F (2005)Erratum: Suppression of D'yakonov-Perel Spin Relaxation in InAs and InSb by n-Type Doping at 300 K (vol 83, pg 5220, 2003), In: Applied Physics Letters87(12)
Litvinenko KL, Leontiadou MA, Li J, Clowes SK, Emeny MT, Ashley T, Pidgeon CR, Cohen LF, Murdin BN (2010)Strong dependence of spin dynamics on the orientation of an external magnetic field for InSb and InAs, In: APPLIED PHYSICS LETTERS96(11)ARTN 1pp. ?-? AMER INST PHYSICS
Murzyn P, Pidgeon C R, Phillips P J, Merrick M, Litvinenko K L, Jefferson J H, Allam J, Murdin B N, Ashley T, Miller A, Cohen L F (2003)Suppression of D'yakonov-Perel Spin Relaxation in InAs and InSb by n-Type Doping at 300 K, In: Applied Physics Letters83(25)

We have made direct pump-probe measurements of spin lifetimes in intrinsic and degenerate n-InAs at 300 K. In particular, we measure remarkably long spin lifetimes (tau(s)similar to1.6 ns) for near-degenerate epilayers of n-InAs. For intrinsic material, we determine tau(s)similar to20 ps, in agreement with other workers. There are two main models that have been invoked for describing spin relaxation in narrow-gap semiconductors: the D'yakonov-Perel (DP) model and the Elliott-Yafet (EY) model. For intrinsic material, the DP model is believed to dominate in III-V materials above 77 K, in agreement with our results. We show that in the presence of strong n-type doping, the DP relaxation is suppressed both by the degeneracy condition and by electron-electron scattering, and that the EY model then dominates for the n-type material. We show that this same process is also responsible for a hitherto unexplained lengthening of tau(s) with n-type doping in our earlier measurements of n-InSb.

Allam J, Sajjad MT, Sutton R, Litvinenko K, Wang Z, Siddique S, Yang Q-H, Loh WH, Brown T (2013)Measurement of a reaction-diffusion crossover in exciton-exciton recombination inside carbon nanotubes using femtosecond optical absorption, In: Physical Review Letters American Physical Society
Exciton-exciton recombination in isolated semiconducting single-walled carbon nanotubes was studied using femtosecond transient absorption. Under sufficient excitation to saturate the optical absorption, we observed an abrupt transition between reaction- and diffusion- limited kinetics, arising from reactions between incoherent localized excitons with a finite probability of ~ 0.2 per encounter. This represents the first experimental observation of a crossover between classical and critical kinetics in a 1D coalescing random walk, which is a paradigm for the study of non- equilibrium systems.
Litvinenko K L, Murdin B N, Allam J, Pidgeon C R, Clowes S K, Bird M, Morris K, Branford W, Cohen L F, Ashley T, Buckle L (2006)Spin Relaxation in N-InSb/AlInSb Quantum Wells, In: New Journal of Physics8(4)

We have used time resolved spectroscopy to measure the relaxation of spin polarization in InSb/AlInSb quantum wells (QWs) as a function of temperature and mobility. The results are consistent with the D'yakonov - Perel (DP) mechanism for high mobility samples over the temperature range from 50 to 300 K. For low mobility samples at high temperature the Elliott - Yafet and DP mechanisms become comparable. We show that the mobility can in certain circumstances determine which mechanism is dominant, and that above 1 m(2) V-1 s(-1) in 20 nm wide InSb QWs it is the DP mechanism. We also give a criterion for the maximum spin lifetime in terms of mobility and temperature, and show that for our 20 nm wide QWs this corresponds to 0.5 ps at 300 K and mobility 1 m(2) V-1 s(-1).

Murzyn P., Pidgeon C. R., Phillips P. J., Merrick M., Litvinenko K. L., Allam J., Murdin B. N., Ashley T., Jefferson J. H., Miller A., Cohen L. F. (2003)Suppression of D'yakonov–Perel spin relaxation in InAs and InSb by n-type doping at 300 K, In: Applied Physics Letters5220(2003)
Lynch SA, Greenland PT, Vinh NQ, Litvinenko K, Redlich B, van der Meer L, Warner M, Stoneham AM, Aeppli G, Pidgeon CR, Murdin BN (2008)Lifetime Measurements of Group V Donor Rydberg States in Silicon at THz Frequencies, In: 2008 5TH IEEE INTERNATIONAL CONFERENCE ON GROUP IV PHOTONICSpp. 24-26
Murdin B N, Litvinenko K, Clarke D G, Pidgeon C R, Murzyn P, Phillips P J, Carder D, Berden G, Redlich B, van der Meer A F, Clowes S, Harris J J, Cohen L F, Ashley T, Buckle L (2006)Spin Relaxation by Transient Monopolar and Bipolar Optical Orientation, In: Physical Review Letters96(9)

We have used two-color time-resolved spectroscopy to measure the relaxation of electron spin polarizations in a bulk semiconductor. The circularly polarized pump beam induces a polarization either by direct excitation from the valence band, or by free-carrier (Drude) absorption when tuned to an energy below the band gap. We find that the spin relaxation time, measured with picosecond time resolution by resonant induced Faraday rotation in both cases, increases in the presence of photogenerated holes. In the case of the material chosen, n-InSb, the increase was from 14 to 38 ps.

Andreev Y, Kokh AE, Kokh KA, Lanskii GV, Litvinenko Konstantin, Mamrashev AA, Molloy JF, Murdin Benedict, Naftaly M, Nikolaev NA, Svetlichnyi VA (2017)Observation of a different birefringence order at optical and THz frequencies in LBO crystal, In: Optical Materials66pp. 94-97 Elsevier
THz optical properties of lithium borate (LBO) crystals were measured using time-domain spectroscopy (TDS). The LBO crystal samples were of high optical quality and were cut and polished along the h100i, h010i and h001i axes. Two independent measurements were performed in order to con rm the reproducibility and consistency of results. The contradictions in the previously published data on the THz optical properties of LBO were clari ed. It was shown that the birefringence order at THz frequencies is nz < nx < ny, whereas at optical frequencies it is known to be nx < ny < nz. It was seen that nz, which has the highest value in the visible, has the lowest value at THz. This is explained in terms of ionic polarizability and is consistent with the fact that the THz absorption coe cient for a wave polarized along the Z-axis is more than an order of magnitude lower than for the X and Y axes. Absorption as low as 0.2 cm 1 was found at frequencies up to 0.5 THz for a wave polarized parallel to the Z-axis. A set of new dispersion equations was designed for the entire transparency range.
Wright NM, Thomson DJ, Litvinenko KL, Headley WR, Smith AJ, Knights AP, Deane JHB, Gardes FY, Mashanovich GZ, Gwilliam R, Reed GT (2009)Free carrier lifetime modification in silicon, In: Proceedings of SPIE - The International Society for Optical Engineering7220
Pidgeon CR, Murzyn P, Phillips PJ, Murdin BN, Litvinenko K, Merrick M, Cohen LF, Zhang T, Clowes SK, Buckle P, Ashley T, Thumm M, Wiesbeck W (2004)Spin relaxation in InSb and InAs by 1-and 2-colour spectroscopy with free electron and solid state lasers, In: CONFERENCE DIGEST OF THE 2004 JOINT 29TH INTERNATIONAL CONFERENCE ON INFRARED AND MILLIMETER WAVES AND 12TH INTERNATIONAL CONFERENCE ON TERAHERTZ ELECTRONICSpp. 207-208
Murdin B. N., Litvinenko K., Allam J., Pidgeon C. R., Bird M., Morrison K., Zhang T., Clowes S. K., Branford W. R., Harris J., Cohen L. F. (2005)Temperature and doping dependence of spin relaxation in n-InAs, In: Physical Review B72(085346)

We have used time-resolved spectroscopy to measure the relaxation of spin polarizations in the narrow gap semiconductor material n-InAs as a function of temperature, doping, and pump wavelength. The results are consistent with the D'Yakonov-Perel mechanism for temperatures between 77 and 300 K. However, the data suggest that electron-electron scattering should be taken into account in determining the dependence of the spin lifetime on the carrier concentration in the range 5.2×1016–8.8×1017 cm–3. For a sample with doping of 1.22×1017 cm–3 the spin lifetime was 24 ps at room temperature. By applying a magnetic field in the sample plane we also observed coherent precession of the spins in the time domain, with a g>/i> factor g*=–13, also at room temperature.

Leontiadou MA, Litvinenko KL, Clowes SK, Springholz G, Schwarzl T, Eibelhuber M, Heiss W, Pidgeon CR, Murdin BN (2011)Substantial temperature dependence of transverse electron g*-factor in lead chalcogenide multi-quantum wells, In: AIP Conference Proceedings1416pp. 178-180
We report significant temperature dependence of the transverse electron g∗‐factor in symmetric lead chalcogenide multi‐quantum wells (MQWs). The g∗‐factor values were extracted from the electron Larmor precessions recorded by means of a circularly polarized pump probe technique under the influence of transverse external magnetic field (Voigt geometry) in the temperature range between 10 and 150K. The reported g∗‐factor values are in good agreement with theoretical predictions and available low temperature experimental data. Although temperature tuning of lead salt laser emission wavelengths has been the method of choice in these systems for many years, we demonstrate that temperature can also be used to modulate g∗, and hence the spin lifetime in lead salt QW spintronic devices.
Pidgeon C R, Harris J J, Zhang T, Cohen L F, Murdin B N, Litvinenko K L, Nikzad L, Allam J (2007)Spin Lifetime in High Quality InSb Epitaxial Layers Grown on GaAs, In: Journal of Applied Physics101(8)

The spin relaxation in undoped InSb films grown on GaAs has been investigated in the temperature range from 77 to 290 K. Two distinct lifetime values have been extracted, 1 and 2.5 ps, dependent on film thickness. Comparison of this data with a multilayer transport analysis of the films suggests that the longer time (similar to 2.5 ps at 290 K) is associated with the central intrinsic region of the film, while the shorter time (similar to 1 ps) is related to the highly dislocated accumulation region at the film-substrate interface. Whereas previous work on InAs films grown on GaAs showed that the native surface defect resulted in an additional charge accumulation layer with high conductivity but very short spin lifetime, in InSb layers the surface states introduce a depletion region. We infer that InSb could be a more attractive candidate for spintronic applications than InAs.

Headley WR, Smith AJ, Knights AP, Jessop PE, Tarr NG, Deane JHB, Reed GT, Mashanovich G, Gardes FY, Gwilliam RM, Wright NM, Thomson DJ, Timotijevic BD, Litvinenko KL (2009)Silicon photonics at the University of Surrey, In: Proceedings of SPIE - The International Society for Optical Engineering7366pp. 736602.1-736602.12
Silicon Photonics is a field that has seen rapid growth and dramatic changes in the past 5 years. According to the MIT Communications Technology Roadmap [1], which aims to establish a common architecture platform across market sectors with a potential $20B in annual revenue, silicon photonics is among the top ten emerging technologies. This has in part been a consequence of the recent involvement of large semiconductor companies around the world, particularly in the USA. Significant investment in the technology has also followed in Japan, Korea, and in the European Union. Low cost is a key driver, so it is imperative to pursue technologies that are mass-producible. Therefore, Silicon Photonics continues to progress at a rapid rate. This paper will describe some of the work of the Silicon Photonics Group at the University of Surrey in the UK. The work is concerned with the sequential development of a series of components for silicon photonic optical circuits, and some of the components are discussed here. In particular the paper will present work on optical waveguides, optical filters, modulators, and lifetime modification of carriers generated by two photon absorption, to improve the performance of Raman amplifiers in silicon.
Litvinenko K. L., Murdin B. N., Allam J., Pidgeon C. R., Zhang T., Harris J. J., Cohen L. F., Eustace D. A., McComb D. W. (2006)Spin lifetime in InAs epitaxial layers grown on GaAs, In: Physical Review B74(075331)

We report investigation of the spin relaxation in InAs films grown on GaAs at a temperature range from 77 K to 290 K. InAs is known to have a surface accumulation layer and the depth profile of the concentration and mobility is strongly nonuniform. We have correlated the spin relaxation with a multilayer analysis of the transport properties and find that the surface and the interface with the GaAs substrate both have subpicosecond lifetimes (due to the high carrier concentration), whereas the central semiconducting layer has a lifetime of an order of 10 ps. Even for the thickest film studied (1 micro-m, the semiconducting layer only carried 30% of the total current (with 10% through the interface layer and 60% through the surface accumulation layer). Designs for spintronic devices that utilize InAs, which is attractive due to its narrow gap and strong Rashba effect, will need to include strategies for minimizing the effects of the surface.

Litvinenko KL, Bowyer ET, Greenland PT, Stavrias N, Li J, Gwilliam R, Villis BJ, Matmon G, Pang MLY, Redlich B, van der Meer AFG, Pidgeon CR, Aeppli G, Murdin BN (2015)Coherent creation and destruction of orbital wavepackets in Si:P with electrical and optical read-out, In: NATURE COMMUNICATIONS6ARTN 6pp. ?-? NATURE PUBLISHING GROUP
Litvinenko K, Greenland PT, Redlich B, Pidgeon CR, Aeppli G, Murdin BN (2017)Weak probe readout of coherent impurity orbital superpositions in silicon, In: Physical Review B - Condensed Matter and Materials Physics American Physical Society
Pump-probe spectroscopy is the most common time-resolved technique for investigation of electronic dynamics, and the results provide the incoherent population decay time T1. Here we use a modified pump-probe experiment to investigate coherent dynamics, and we demonstrate this with a measurement of the inhomogeneous dephasing time T2* for phosphorus impurities in silicon. The pulse sequence produces the same information as previous coherent all-optical (photon-echo-based) techniques but is simpler. The probe signal strength is first order in pulse area but its effect on the target state is only second order, meaning that it does not demolish the quantum information. We propose simple extensions to the technique to measure the homogeneous dephasing time T2, or to perform tomography of the target qubit.
Bowyer ET, Villis BJ, Li J, Litvinenko KL, Murdin BN, Erfani M, Matmon G, Aeppli G, Ortega J-M, Prazeres R, Dong L, Yu X (2014)Picosecond dynamics of a silicon donor based terahertz detector device, In: App. Phys. Lett105pp. 021107-021107
Litvinenko K. L., Murdin B. N., Allam J., Pidgeon C. R., Bird M., Morris K., Branford W., Clowes S. K., Cohen L. F., Ashley T., Buckle L. (2006)Spin relaxation in n-InSb/AlInSb quantum wells, In: New Journal of Physics8(4)

We have used time resolved spectroscopy to measure the relaxation of spin polarization in InSb/AlInSb quantum wells (QWs) as a function of temperature and mobility. The results are consistent with the D'yakonov–Perel (DP) mechanism for high mobility samples over the temperature range from 50 to 300 K. For low mobility samples at high temperature the Elliott–Yafet and DP mechanisms become comparable. We show that the mobility can in certain circumstances determine which mechanism is dominant, and that above 1 m2 V-1 s-1 in 20 nm wide InSb QWs it is the DP mechanism. We also give a criterion for the maximum spin lifetime in terms of mobility and temperature, and show that for our 20 nm wide QWs this corresponds to 0.5 ps at 300 K and mobility 1 m2 V-1 s-1.

Lynch SA, Matmon G, Pavlov SG, Litvinenko KL, Redlich B, Van Der Meer AFG, Abrosimov NV, Hübers H-W (2010)Inhomogeneous broadening of phosphorus donor lines in the far-infrared spectra of single-crystalline SiGe, In: Physical Review B - Condensed Matter and Materials Physics82(24)
Litvinenko KL, Pang M, Li J, Bowyer E, Engelkamp H, Shuman VB, Portsel LM, Lodygin AN, Astrov YA, Pavlov SG, Huebers H-W, Pidgeon CR, Murdin BN (2014)High-field impurity magneto-optics of Si:Se, In: PHYSICAL REVIEW B90(11)ARTN 1pp. ?-? AMER PHYSICAL SOC
Redlich B., van der Meer A. F. G., Clowes S., Harris J. J., Cohen L. F., Ashley T., Buckle L., Pidgeon C. R., Murdin B. N., Litvinenko K., Clarke D. G., Murzyn P., Phillips P. J., Carder D., Berden G. (2006)Spin Relaxation by Transient Monopolar and Bipolar Optical Orientation, In: Physical Review Letters96(096603)

We have used two-color time-resolved spectroscopy to measure the relaxation of electron spin polarizations in a bulk semiconductor. The circularly polarized pump beam induces a polarization either by direct excitation from the valence band, or by free-carrier (Drude) absorption when tuned to an energy below the band gap. We find that the spin relaxation time, measured with picosecond time resolution by resonant induced Faraday rotation in both cases, increases in the presence of photogenerated holes. In the case of the material chosen, n-InSb, the increase was from 14 to 38 ps.

Litvinenko K L, Murdin B N, Allam J, Pidgeon C R, Zhang T, Harris J J, Cohen L F, Eustace D A, McComb D W (2006)Spin Lifetime in InAs Epitaxial Layers Grown on GaAs, In: Physical Review B74(7)

We report investigation of the spin relaxation in InAs films grown on GaAs at a temperature range from 77 K to 290 K. InAs is known to have a surface accumulation layer and the depth profile of the concentration and mobility is strongly nonuniform. We have correlated the spin relaxation with a multilayer analysis of the transport properties and find that the surface and the interface with the GaAs substrate both have subpicosecond lifetimes (due to the high carrier concentration), whereas the central semiconducting layer has a lifetime of an order of 10 ps. Even for the thickest film studied (1 mu m), the semiconducting layer only carried 30% of the total current (with 10% through the interface layer and 60% through the surface accumulation layer). Designs for spintronic devices that utilize InAs, which is attractive due to its narrow gap and strong Rashba effect, will need to include strategies for minimizing the effects of the surface.

Litvinenko KL, Nikzad L, Pidgeon CR, Allam J, Cohen LF, Ashley T, Emeny M, Zawadzki W, Murdin BN (2008)Temperature dependence of the electron Lande g factor in InSb and GaAs, In: PHYSICAL REVIEW B77(3)ARTN 0pp. ?-? AMER PHYSICAL SOC