Dr Priya Sharma
About
Biography
I embarked on a career in physics research with an Engineering Physics degree from the Indian Institute of Technology Bombay, India. I worked on the effects of disorder in superfluid helium-3 as the topic of my PhD thesis in theoretical condensed matter physics at Northwestern University, USA. Subsequently, I held a Leverhulme Early Career Fellowship at Royal Holloway University of London where I studied the effects of surface roughness in confined helium-3. I was awarded a Fellowship from the Department of Science and Technology, Government of India and worked at the Indian Institute of Science, Bangalore on theoretical studies of disordered Fermi liquids. More recently, I developed a proposal to study the interaction of qubits with superfluid helium-3 and currently hold a Daphne Jackson Fellowship to pursue this investigation at the University of Surrey.
Areas of specialism
News
Life Scientific Short
Thanks to Prof. Jim Al-Khalili, CBE FRS HonFREng HonFIET HonFinstP, for producing this Short (2-min video) on my invention of a new type of quantum bit, that could be used to make quantum computers.
ResearchResearch interests
I am interested in one of the paradigms for complex symmetry-breaking in topologically ordered systems, superfluid helium-3. I have worked on the effects of disorder and confinement, which have fascinating consequences in this quantum system. I am a theorist and work on the mechanisms and implications of superconductivity and superfluidity. I have recently invented a superfluid-based quantum device that could function as a novel qubit.
Research interests
I am interested in one of the paradigms for complex symmetry-breaking in topologically ordered systems, superfluid helium-3. I have worked on the effects of disorder and confinement, which have fascinating consequences in this quantum system. I am a theorist and work on the mechanisms and implications of superconductivity and superfluidity. I have recently invented a superfluid-based quantum device that could function as a novel qubit.
Publications
We report theoretical results for heat transport by quasiparticle excitations in superfluid He infused into silica aerogel engineered with uniaxial anisotropy. For this system, two distinct equal spin pairing (ESP) superfluid phases have been reported based on NMR spectroscopy. Theoretical analysis predicts the first ESP state to be the chiral A phase with chiral axis aligned along the strain axis, and the lower temperature phase to be a polar-distorted chiral phase with random transverse fluctuations in the orientation of the chiral axis. We report calculations of heat transport for the high temperature chiral phase, including an anomalous (zero field) thermal Hall current originating from branch conversion scattering of Bogoliubov quasiparticles by the chiral order parameter induced by potential scattering by the silica aerogel. Observation of an anomalous thermal Hall current would provide a direct signature of the underlying chirality and topology of the superfluid phase of He in “stretched” silica aerogels.
Superfluid He-3, with unconventional spin-triplet p-wave pairing, provides a model system for topological superconductors, which have attracted significant interest through potential applications in topologically protected quantum computing. In topological insulators and quantum Hall systems, the surface/edge states, arising from bulk-surface correspondence and the momentum space topology of the band structure, are robust. Here we demonstrate that in topological superfluids and superconductors the surface Andreev bound states, which depend on the momentum space topology of the emergent order parameter, are fragile with respect to the details of surface scattering. We confine superfluid He-3 within a cavity of height D comparable to the Cooper pair diameter xi(0). We precisely determine the superfluid transition temperature T-c and the suppression of the superfluid energy gap, for different scattering conditions tuned in situ, and compare to the predictions of quasiclassical theory. We discover that surface magnetic scattering leads to unexpectedly large suppression of T-c, corresponding to an increased density of low energy bound states.
Quasiclassical equations with manifest gauge invariance are discussed in the context of unconventional singlet superconducting states in the static limit. Deviations of the quasiclassical propagator from its equilibrium solutions in the presence of magnetic fields and Hall terms are analysed in terms of a "small" parameter and a formulation developed to first order in "small". A modified quasiclassical propagator is defined to this order that is a solution of a new gauge-invariant Eilenberger-like equation with a normalization condition. A Riccati parametrization with manifest gauge invariance is proposed. Riccati equations are derived to leading order in "small" that are directly applicable to superconducting systems in the presence of magnetic fields.
Additional publications
1. “Light Induced Orbital Magnetism in Metals via Inverse Faraday Effect”, Priya Sharma, A. V. Balatsky, Phys. Rev., 110, 094302 (2024) https://doi.org/10.1103/PhysRevB.110.094302
2. “Proposal to Observe Transverse Sound in Normal Liquid 3He in Aerogel”, Priya Sharma, J. Low Temp. Phys. 215, 397 (2024) https://doi.org/10.1007/s10909-024-03065-6
3. “Light Induced Magnetism in Metals via Inverse Faraday Effect”, Priya Sharma, A. V. Balatsky, https://arxiv.org/abs/2303.01699
4. “Disorder Induced Anomalous Thermal Hall Effect in Chiral Phases of Superfluid 3He”, Priya Sharma, Anton B. Vorontsov, J. A. Sauls, JPS Conf. Proc. 38, 011002 (2023)
5. “Anomalous Thermal Hall Effect in Chiral Phases of 3He-Aerogel, Priya Sharma, J. A. Sauls, J. Low. Temp. Phys. 208, 341(2022)
6. ”Fragility of Surface States in Topological Superfluid 3He”, P. J. Heikkinen, A. Casey, L. V. Levitin, X. Rojas, A. Vorontsov, P. Sharma, N. Zhelev, J. M. Parpia, J. Saunders, Nature Communications 12, 1574 (2021)
7. ”Approach to Solving Quasiclassical Equations with Gauge Invariance”, P. Sharma, J. Low. Temp. Phys. 201, 73 (2020)
8. ”Anomalous Heat and Momentum Transport Arising from Surface Roughness in a Normal 3He Slab”, Priya Sharma, JETP, 126 201(2018)
9. ”First-principles theory of electronic structure and spin-phonon coupling in hexagonal anti- ferromagnetic YMnO3”, Arpita Paul, Priya Sharma, Umesh V. Waghmare, Phys. Rev. B 92, 054106 (2015)
10. ”Transport in Fermi Liquids Confined by Rough Walls”, P. Sharma, JLTP 177, 3(2014)
11. ”Effect of Rough Walls on Transport in Mesoscopic 3He Films”, P. Sharma, A. Corcoles, R.G. Bennett, J.M. Parpia, B. Cowan, J. Saunders, JLTP 171(5-6), 725 (2013)
12. ”Quantum Transport in Mesoscopic 3He Films : Experimental Study of the Interference of Bulk and Boundary Scattering”, P. Sharma, A. Corcoles, R. G. Bennett, J. M. Parpia, B. Cowan, A. Casey, J. Saunders, Phys. Rev. Lett. 107, 196805 (2011)
13. ”Mass Coupling and Q-1 of Impurity-Limited Normal 3He in a Torsion Pendulum”, R. G. Bennett, A. D. Fefferman, N. Zhelev, K. Y. Fang, J. Pollanen, P. Sharma, W. P. Halperin, J. Parpia, JLTP 162, 172 (2011)
14. ”Theory of Heat Transport of Normal Liquid 3He in Aerogel”, J. A.Sauls, P. Sharma, New J. Phys. 12, 083056 (2010)
15. ”Transport in Mesoscopic 3He Films on Rough Surfaces”, P. Sharma, A. Corcoles, A. Casey, S. Dimov, J. Parpia, B. Cowan, J. Saunders, JLTP 158, 220(2010)
16. ”Magnetization and Spin Diffusion of Liquid 3He in Aerogel”, J. A. Sauls, Yu. M. Bunkov, E. Collin, H. Godfrin, P. Sharma, Phy. Rev. B 72, 024507(2005)
17. ”Specific Heat of Disordered Superfluid 3He in Aerogel”, H. Choi, K. Yawata, T. M. Haard, J. P. Davis, G. Gervais, N. Mulders, P. Sharma, J. A. Sauls, W. P. Halperin, Phys. Rev. Lett. 93, 145301 (2004)
18. ”Thermal Conductivity of Superfluid 3He in Aerogel”, Priya Sharma, J. A. Sauls, Physica B 329-333, 313 (2003)
19. ”Impurity Effects on the A1-A2 Splitting of 3He in Aerogel”, J. A. Sauls, Priya Sharma, Phys. Rev. B 68, 224502(2003)
20. ”Magnetic Susceptibility of the Balian-Werthamer Phase of 3He in Aerogel”, Priya Sharma, J. A. Sauls, JLTP 125, 115 (2001)
21. ”Transport Properties of Normal Liquid 3He in Aerogel”, Priya Sharma, J. A. Sauls, Physica B 284-288, 297 (2000)