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Dr Konstantin (Constantine) Litvinenko


Research Fellow (II) / Teaching Fellow
BSc, MSc, PhD

Academic and research departments

Advanced Technology Institute.

My publications

Publications

Pidgeon CR, Murzyn P, Phillips PJ, Murdin BN, Litvinenko K, Merrick M, Cohen LF, Zhang T, Clowes SK, Buckle P, Ashley T (2004) Spin relaxation in InSb and InAs by 1-and 2-colour spectroscopy with free electron and solid state lasers, CONFERENCE DIGEST OF THE 2004 JOINT 29TH INTERNATIONAL CONFERENCE ON INFRARED AND MILLIMETER WAVES AND 12TH INTERNATIONAL CONFERENCE ON TERAHERTZ ELECTRONICS pp. 207-208 IEEE
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, JOURNAL OF PHYSICS-CONDENSED MATTER 23 (3) ARTN 035801 IOP PUBLISHING LTD
Murdin BN, Li J, Pang MLY, Bowyer ET, Litvinenko KL, Clowes SK, Engelkamp H, Pidgeon CR, Galbraith I, Abrosimov NV, Riemann H, Pavlov SG, Huebers H-W, Murdin PG (2013) Si:P as a laboratory analogue for hydrogen on high magnetic field white dwarf stars, NATURE COMMUNICATIONS 4 ARTN 1469 NATURE PUBLISHING GROUP
Litvinenko KL, Nikzad L, Allam J, Murdin BN, Pidgeon CR, Harris JJ, Zhang T, Cohen LF (2007) Spin lifetime in high quality InSb epitaxial layers grown on GaAs, JOURNAL OF APPLIED PHYSICS 101 (8) AMER INST PHYSICS
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, ULTRAFAST PHENOMENA IN SEMICONDUCTORS 297-2 pp. 11-16 TRANSTEC PUBLICATIONS LTD
Murdin BN, Litvinenko K, Clarke DG, Pidgeon CR, Murzyn P, Phillips PJ, Carder D, Berden G, Redlich B, van der Meer AFG, Clowes S, Harris JJ, Cohen LF, Ashley T, Buckle L (2006) Spin relaxation by transient monopolar and bipolar optical orientation, PHYSICAL REVIEW LETTERS 96 (9) ARTN 096603 AMERICAN PHYSICAL SOC
Allam J, Sutton R, Sajjad M, Litvinenko K, Wang Z, Siddique S, Yang Q-H, Brown T, Loh W (2010) Exciton reaction on carbon nanotubes: role of spatial distribution,
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, STATE-OF-THE-ART PROGRAM ON COMPOUND SEMICONDUCTORS XL (SOTAPOCS XL) AND NARROW BANDGAP OPTOELECTRONIC MATERIALS AND DEVICES II 2004 (2) pp. 253-258 ELECTROCHEMICAL SOCIETY INC
Litvinenko K, Kohler K, Leo K, Loser F, Lyssenko VG (1999) Nonharmonic Bloch oscillations in GaAs/AlGaAs superlattices, ULTRAFAST PHENOMENA IN SEMICONDUCTORS 297-2 pp. 17-20 TRANSTEC PUBLICATIONS LTD
Thomson DJ, Reed GT, Knights AP, Yang PY, Gardes FY, Smith AJ, Litvinenko KL (2010) Total Internal Reflection Optical Switch in SOI With Defect Engineered Barrier Region, JOURNAL OF LIGHTWAVE TECHNOLOGY 28 (17) pp. 2483-2491 IEEE-INST ELECTRICAL ELECTRONICS ENGINEERS INC
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, PHYSICAL REVIEW B 81 (3) ARTN 033201 AMER PHYSICAL SOC
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, JOURNAL OF LUMINESCENCE 72-4 pp. 457-458 ELSEVIER SCIENCE BV
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, PHYSICAL REVIEW B 88 (3) ARTN 035201 AMER PHYSICAL SOC
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, PROCEEDINGS OF THE NATIONAL ACADEMY OF SCIENCES OF THE UNITED STATES OF AMERICA 105 (31) pp. 10649-10653 NATL ACAD SCIENCES
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, NARROW GAP SEMICONDUCTORS 2007 119 pp. 19-21 SPRINGER
Litvinenko K, Leontiadou M, Li J, Bowyer E, Clowes S, Pidgeon CR, Murdin B (2011) Manipulation of spin dynamics in semiconductor structures by orientation of small external magnetic field, AIP Conference Proceedings 1399 pp. 657-658 American Institute of Physics
Electron spin relaxation times have been measured in InSb and InAs quantum wells and epi-layers in a moderate (
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, NARROW GAP SEMICONDUCTORS 2007 119 pp. 27-29 SPRINGER
Wright NM, Thomson DJ, Litvinenko KL, Headley WR, Smith AJ, Knights AP, Deane JHB, Gardes FY, Mashanovich GZ, Gwilliam R, Reed GT (2008) Free carrier lifetime modification for silicon waveguide based devices, OPT EXPRESS 16 (24) pp. 19779-19784 OPTICAL SOC AMER
We investigate the effect of silicon ion irradiation on free carrier lifetime in silicon waveguides, and thus its ability to reduce the density of two-photon-absorption (TPA) generated free carriers. Our experimental results show that free carrier lifetime can be reduced significantly by silicon ion implantation. Associated excess optical absorption from the implanted ions can be reduced to an acceptable level if irradiation energy and dose are correctly chosen. Simulations of Raman scattering suggest that net gain can be achieved in certain cases without the need for an integrated diode in reverse bias to remove the photo-generated free carriers. (c) 2008 Optical Society of America
Leontiadoa M, Clowes S, Litvinenko K, Pidgeon C, Ashley T, Emeny M, Murdin B (2009) Variable g-factor spin relaxation in InSb in an external magnetic field,
Litvinenko KL, Murdin BN, Allam J, Pidgeon CR, Zhang T, Harris JJ, Cohen LF, Eustace DA, McComb DW (2006) Spin lifetime in InAs epitaxial layers grown on GaAs, PHYSICAL REVIEW B 74 (7) ARTN 075331 AMERICAN PHYSICAL SOC
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, SILICON PHOTONICS V 7606 ARTN 76060H SPIE-INT SOC OPTICAL ENGINEERING
Saeedi K, Szech M, Dluhy P, Salvail JZ, Morse KJ, Riemann H, Abrosimov NV, Nötzel N, Litvinenko KL, Murdin BN, Thewalt ML (2015) Optical pumping and readout of bismuth hyperfine states in silicon for atomic clock applications., Sci Rep 5
The push for a semiconductor-based quantum information technology has renewed interest in the spin states and optical transitions of shallow donors in silicon, including the donor bound exciton transitions in the near-infrared and the Rydberg, or hydrogenic, transitions in the mid-infrared. The deepest group V donor in silicon, bismuth, has a large zero-field ground state hyperfine splitting, comparable to that of rubidium, upon which the now-ubiquitous rubidium atomic clock time standard is based. Here we show that the ground state hyperfine populations of bismuth can be read out using the mid-infrared Rydberg transitions, analogous to the optical readout of the rubidium ground state populations upon which rubidium clock technology is based. We further use these transitions to demonstrate strong population pumping by resonant excitation of the bound exciton transitions, suggesting several possible approaches to a solid-state atomic clock using bismuth in silicon, or eventually in enriched (28)Si.
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, Springer Proceedings in Physics 159 pp. 92-93
Allam J, Sutton R, Sajjad M, Litvinenko K, Wang Z, Siddique S, Yang Q, Brown T, Loh W (2010) Reaction, diffusion and dissociation of excitons on carbon nanotubes, 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
Litvinenko KL, Bowyer ET, Greenland PT, Stavrias N, Li J, Gwilliam R, Villis BJ, Matmon G, Pang ML, Redlich B, van der Meer AF, Pidgeon CR, Aeppli G, Murdin BN (2015) Coherent creation and destruction of orbital wavepackets in Si:P with electrical and optical read-out., Nat Commun 6
The ability to control dynamics of quantum states by optical interference, and subsequent electrical read-out, is crucial for solid state quantum technologies. Ramsey interference has been successfully observed for spins in silicon and nitrogen vacancy centres in diamond, and for orbital motion in InAs quantum dots. Here we demonstrate terahertz optical excitation, manipulation and destruction via Ramsey interference of orbital wavepackets in Si:P with electrical read-out. We show milliradian control over the wavefunction phase for the two-level system formed by the 1s and 2p states. The results have been verified by all-optical echo detection methods, sensitive only to coherent excitations in the sample. The experiments open a route to exploitation of donors in silicon for atom trap physics, with concomitant potential for quantum computing schemes, which rely on orbital superpositions to, for example, gate the magnetic exchange interactions between impurities.
Bowyer ET, Villis BJ, Li J, Litvinenko KL, Murdin BN, Erfani M, Matmon G, Aeppli G, Ortega JM, Prazeres R, Dong L, Yu X (2014) Picosecond dynamics of a silicon donor based terahertz detector device, Applied Physics Letters 105 (2)
We report the characteristics of a simple complementary metal-oxide-semiconductor compatible terahertz detector device with low response time (nanoseconds) determined using a short-pulse, high intensity free-electron laser. The noise equivalent power was 1 × 10-11 W Hz -1/2. The detector has an enhanced response over narrow bands, most notably at 9.5 THz, with a continuum response at higher frequencies. Using such a device, the dynamics of donors in silicon can be explored, a system which has great potential for quantum information processing. © 2014 AIP Publishing LLC.
Li J, Gilbertson AM, Litvinenko KL, Cohen LF, Clowes SK (2012) Observation of spin dependent photocoductivity in InSb quantum well nanowires, Applied Physics Letters 101 (15)
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 (H 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 (H 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.
Murdin BN, Litvinenko K, Allam J, Pidgeon CR, Bird M, Morrison K, Zhang T, Clowes SK, Branford WR, Harris J, Cohen LF (2005) Temperature and doping dependence of spin relaxation in n-InAs, PHYSICAL REVIEW B 72 (8) ARTN 085346 AMERICAN PHYSICAL SOC
Lynch SA, Matmon G, Pavlov SG, Litvinenko KL, Redlich B, Van Der Meer AFG, Abrosimov NV, Hübers H-W (2011) Inhomogeneous broadening of phosphorus donor lines in the far-infrared spectra of single-crystalline SiGe, Physical Review B - Condensed Matter and Materials Physics 82 (24)
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,
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, AIP Conference Proceedings 1416 pp. 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. © 2011 American Institute of Physics.
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 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, APPLIED PHYSICS LETTERS 96 (11) ARTN 111107 AMER INST PHYSICS
Litvinenko KL, Nikzad L, Allam J, Murdin BN, Pidgeon CR, Harris JJ, Cohen LF (2007) Spin dynamics in narrow-gap semiconductor epitaxial layers, JOURNAL OF SUPERCONDUCTIVITY AND NOVEL MAGNETISM 20 (6) pp. 461-465 SPRINGER
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, Proceedings of SPIE - The International Society for Optical Engineering 7220
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, PHYSICAL REVIEW B 77 (3) ARTN 033204 AMER PHYSICAL SOC
Litvinenko K, Birkedal D, Lyssenko VG, Hvam JM (1999) Exciton dynamics in GaAs/AlxGa1-xAs quantum wells, PHYSICAL REVIEW B 59 (15) pp. 10255-10260 AMER PHYSICAL SOC
Allam J, Sutton R, Sjjad M, Litvinenko K, Siddique S, Wang Z, Yang Q, Brwon T, Loh W (2010) Reaction, diffusion and dissociation of excitons on carbon nanotubes, OSA Technical Digest (CD) The Optical Society
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.
Reed GT, Mashanovich G, Gardes FY, Gwilliam RM, Wright NM, Thomson DJ, Timotijevic BD, Litvinenko KL, Headley WR, Smith AJ, Knights AP, Jessop PE, Tarr NG, Deane JHB (2009) Silicon photonics at the University of Surrey, Proceedings of SPIE - The International Society for Optical Engineering 7366 pp. 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.
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,
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 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, PHYSICAL REVIEW B 90 (11) ARTN 115204 AMER PHYSICAL SOC
Leontiadou M, Clowes S, Litvinenko K, Pidgeon C, Ashley T, Emeny M, Murdin B (2009) Variable g-factor spin relaxation in InSb in an external magnetic field,
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, 2008 5TH IEEE INTERNATIONAL CONFERENCE ON GROUP IV PHOTONICS pp. 24-26 IEEE
Litvinenko KL, Murdin BN, Allam J, Pidgeon CR, Bird M, Morris K, Branford W, Clowes SK, Cohen LF, Ashley T, Buckle L (2006) Spin relaxation in n-InSb/AlInSb quantum wells, NEW JOURNAL OF PHYSICS 8 PII S1367-2630(06)15617-7 IOP PUBLISHING LTD
Wright N, Thomson D, Litvinenko K, Headley W, Smith A, Knights A, Gardes F, Mashanovich G, Gwilliam R, Reed G (2008) Free carrier lifetime modification for silicon waveguide based devices, Proceedings of 5th IEEE International Conference on Group IV Photonics pp. 122-124 IEEE
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.
Litvinenko KL, Pavlov SG, Hübers HW, Abrosimov NV, Pidgeon CR, Murdin BN (2014) Photon assisted tunneling in pairs of silicon donors, Physical Review B - Condensed Matter and Materials Physics 89 (23)
Shallow donors in silicon are favorable candidates for the implementation of solid-state quantum computer architectures because of the promising combination of atomiclike coherence properties and scalability from the semiconductor manufacturing industry. Quantum processing schemes require (among other things) controlled information transfer for readout. Here we demonstrate controlled electron tunneling at 10 K from P to Sb impurities and vice versa with the assistance of resonant terahertz photons. © 2014 American Physical Society.
Litvinenko K, Greenland P, Redlich B, Pidgeon C, Aeppli G, Murdin B (2016) Weak probe readout of coherent impurity orbital superpositions in silicon, Physical Review B - Condensed Matter and Materials Physics 94 (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.
Andreev Y, Kokh A, Kokh K, Lanskii G, Litvinenko K, Mamrashev A, Molloy J, Murdin B, Naftaly M, Nikolaev N, Svetlichnyi V (2017) Observation of a different birefringence order at optical and THz frequencies in LBO crystal, Optical Materials 66 pp. 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
Litvinenko K, Li J, Stavrias N, Meaney A, Christianen P, Engelkamp H, Homewood KP, Pidgeon C, Murdin BN (2016) The Quadratic Zeeman effect used for state-radius determination in neutral donors and donor bound excitons in Si:P, Semiconductor Science and Technology 31 045007 pp. 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.
Li J, Gilbertson A, Litvinenko K, Cohen L, Clowes S (2012) Transverse focusing of spin-polarized photocurrents, 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 ± > 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.
van Loon M, Stavrias Nikolaos, Le N, Litvinenko Konstantin, Greenland P, Pidgeon C, Saeedi K, Redlich B, Aeppli G, Murdin Benedict (2018) Giant multiphoton absorption for THz resonances in silicon hydrogenic donors, Nature Photonics 12 pp. 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.
Litvinenko K, Nikzad L, Allam J, Murdin B, Pidgeon C, Harris J, Zhang T, Cohen L (2007) Spin Lifetime in High Quality InSb Epitaxial Layers Grown on GaAs, Journal of Applied Physics 101 (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.

Murdin B, Litvinenko K, Clarke D, Pidgeon C, Murzyn P, Phillips P, Carder D, Berden G, Redlich B, van der Meer A, Clowes S, Harris J, Cohen L, Ashley T, Buckle L (2006) Spin Relaxation by Transient Monopolar and Bipolar Optical Orientation, Physical Review Letters 96 (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, Murdin B, Allam J, Pidgeon C, Zhang T, Harris J, Cohen L, Eustace D, McComb D (2006) Spin Lifetime in InAs Epitaxial Layers Grown on GaAs, Physical Review B 74 (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 K, Murdin B, Allam J, Pidgeon C, Bird M, Morris K, Branford W, Clowes S, Cohen L, Ashley T, Buckle L (2006) Spin relaxation in n-InSb/AlInSb quantum wells, New Journal of Physics 8 (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.

Litvinenko K, Nikzad L, Allam J, Murdin B, Pidgeon C, Harris J, Zhang T, Cohen L (2007) Spin lifetime in high quality InSb epitaxial layers grown on GaAs, Journal of Applied Physics 083105 (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.

Murzyn P, Pidgeon C, Phillips P, Merrick M, Litvinenko K, Allam J, Murdin B, Ashley T, Jefferson J, Miller A, Cohen L (2003) Suppression of D'yakonov?Perel spin relaxation in InAs and InSb by n-type doping at 300 K, Applied Physics Letters 5220 (2003)
Litvinenko K, Murdin B, Allam J, Pidgeon C, Bird M, Morris K, Branford W, Clowes S, Cohen L, Ashley T, Buckle L (2006) Spin Relaxation in N-InSb/AlInSb Quantum Wells, New Journal of Physics 8 (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).

Murdin B, Litvinenko K, Clarke D, Pidgeon C, Murzyn P, Phillips P, Carder D, Berden G, Redlich B, van der Meer A, Clowes S, Harris J, Cohen L, Ashley T, Buckle L (2006) Spin Relaxation by Transient Monopolar and Bipolar Optical Orientation, Physical Review Letters 96 (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.

Murdin B, Litvinenko K, Allam J, Pidgeon C, Bird M, Morrison K, Zhang T, Clowes S, Branford W, Harris J, Cohen L (2005) Temperature and doping dependence of spin relaxation in n-InAs, Physical Review B 72 (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.

Murdin B, Litvinenko K, Allam J, Pidgeon C, Bird M, Morrison K, Zhang T, Clowes S, Branford W, Harris J, Cohen L (2005) Temperature and Doping Dependence of Spin Relaxation in n-InAs, Physical Review B 72 (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.

Murzyn P, Pidgeon C, Phillips P, Merrick M, Litvinenko K, Allam J, Murdin B, Ashley T, Jefferson J, Miller A, Cohen L (2003) Suppression of D'yakonov-Perel Spin Relaxation in InAs and InSb by n-Type Doping at 300 K, Applied Physics Letters 83 (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.

Litvinenko K, Murdin B, Allam J, Pidgeon C, Zhang T, Harris J, Cohen L, Eustace D, McComb D (2006) Spin lifetime in InAs epitaxial layers grown on GaAs, Physical Review B 74 (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.

Li J, Gilbertson A, Litvinenko K, Cohen L, Clowes S (2012) Transverse focusing of spin-polarized photocurrents, 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 ±0.1eVand that a splitting of the focusing signal is not expected to be observed in linear polarized photocurrent and purely electrical measurements. © 2012 American Physical Society.