Superconductivity

The superconducting phase is commonly characterised by sudden drop of resistance below a certain critical temperature, owing to the formation of a bosonic condensate. Despite past 100 years of work since its discovery, superconductivity is highly relevent in the present day context, be it fundamental research (ex: topological/chiral superconductivity, understanding of pairing mechanism, novel condensate formation, realisation of majorana states etc.), materials discovery or technological advancement like spintronics, qubit generation, quantum technology. My research works in this area encompasses some aspects of the understanding of the vortex state of unconvetional superconductors and evidence of time-reversal symmetry breaking, search of novel coupling effects in ferromagnetic heterostructures and design of artificial quantum systems for odd-frequency spin-triplet state generation for superconducting spintronics.

References

  • R. Khasanov, T. Kondo, M. Bendele, Y. Hamaya, S. J. Ray, S. L. Lee, Tsunehiro Takeuchi- Suppression of the antinodal coherence of superconducting (Bi,Pb)2(Sr,La)2CuO6+δ as revealed by muon spin rotation and angle-resolved photoemission, Physical Review B (Rapid Communication), 82, 020511(R) (2010).

  • D. O. G. Heron, S. J. Ray, S. J. Lister, C. M. Aegerter, H. Keller, P. H. Kes, G. I. Menon, S. L. Lee - Muon-Spin Rotation Measurements of an Unusual Vortex-Glass Phase in the Layered Superconductor Bi2.15Sr1.85CaCu2O8+δ, Physical Review Letters, 110, 107004 (2013).

References

  • S. J. Ray, A. S. Gibbs, S. J. Bending, P. J. Curran, E. Babaev, C. Baines, A. P. Mackenzie, S. L. Lee - Muon-Spin Rotation measurements of the vortex state Sr2RuO4: Type-1.5 superconductivity, vortex clustering and a crossover from a triangular to a square vortex lattice, Physical Review B, 89, 094504 (2014).

References

  • M. Flokstra, S. J. Ray, S.J. Lister, J. Aarts, H. Luetkens, T. Prokscha, A. Suter, E. Morenzoni, S.L. Lee - Measurement of the Spatial Extent of Inverse Proximity in a Py/Nb/Py Superconducting Trilayer using Low-Energy Muon-Spin Rotation, Physical Review B, 89, 054510 (2014).

  • S. J. Ray*, S. J. Lister, S. L. Lee, O. Hellwig, J. Stahn - Stoner enhanced paramagnetic influence on superconductivity in a superconductor/metallic heterostructure, Physica C, 487, 67-71 (2013).

References

  • Eschrig, Matthias. "Spin-polarized supercurrents for spintronics." Phys. Today 64, no. 1 (2011): 43.

  • Linder, Jacob, and Jason WA Robinson. "Superconducting spintronics." Nature Physics 11, no. 4 (2015): 307-315.