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Non-Hermitian Fermi-Dirac Distribution in Persistent Current Transport

Published 14 Mar 2024 in quant-ph, cond-mat.mes-hall, cond-mat.stat-mech, cond-mat.str-el, and cond-mat.supr-con | (2403.09569v2)

Abstract: Persistent currents circulate continuously without requiring external power sources. Here, we extend their theory to include dissipation within the framework of non-Hermitian quantum Hamiltonians. Using Green's function formalism, we introduce a non-Hermitian Fermi-Dirac distribution and derive an analytical expression for the persistent current that relies solely on the complex spectrum. We apply our formula to two dissipative models supporting persistent currents: (i) a phase-biased superconducting-normal-superconducting junction; (ii) a normal ring threaded by a magnetic flux. We show that the persistent currents in both systems exhibit no anomalies at any emergent exceptional points, whose signatures are only discernible in the current susceptibility. We validate our findings by exact diagonalization and extend them to account for finite temperatures and interaction effects. Our formalism offers a general framework for computing quantum many-body observables of non-Hermitian systems in equilibrium, with potential extensions to non-equilibrium scenarios.

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References (52)
  1. Y. Ashida, Z. Gong, and M. Ueda, Non-Hermitian physics, Adv. Phys. 69, 249 (2020).
  2. E. J. Bergholtz, J. C. Budich, and F. K. Kunst, Exceptional topology of non-Hermitian systems, Rev. Mod. Phys. 93, 015005 (2021).
  3. K. Ding, C. Fang, and G. Ma, Non-Hermitian topology and exceptional-point geometries, Nat. Rev. Phys. 4, 745 (2022).
  4. N. Okuma and M. Sato, Non-Hermitian Topological Phenomena: A Review, Annu. Rev. Condens. Matter Phys. 14, 83 (2023).
  5. G. Chen, F. Song, and J. L. Lado, Topological Spin Excitations in Non-Hermitian Spin Chains with a Generalized Kernel Polynomial Algorithm, Phys. Rev. Lett. 130, 100401 (2023).
  6. S. Yao and Z. Wang, Edge States and Topological Invariants of Non-Hermitian Systems, Phys. Rev. Lett. 121, 086803 (2018).
  7. S. Yao, F. Song, and Z. Wang, Non-Hermitian Chern bands, Phys. Rev. Lett. 121, 136802 (2018).
  8. D. Bernard and A. LeClair, A Classification of Non-Hermitian Random Matrices, in Statistical Field Theories, NATO Science Series, edited by A. Cappelli and G. Mussardo (Springer Netherlands, Dordrecht, 2002) pp. 207–214.
  9. A. Altland, M. Fleischhauer, and S. Diehl, Symmetry Classes of Open Fermionic Quantum Matter, Phys. Rev. X 11, 021037 (2021).
  10. L.-W. Yu and D.-L. Deng, Unsupervised Learning of Non-Hermitian Topological Phases, Phys. Rev. Lett. 126, 240402 (2021).
  11. T. Kato, Perturbation Theory for Linear Operators, 2nd ed., Classics in Mathematics (Springer-Verlag, Berlin Heidelberg, 1995).
  12. W. D. Heiss, The physics of exceptional points, J. Phys. A: Math. Theor. 45, 444016 (2012).
  13. G. H. Golub and C. F. Van Loan, Matrix Computations, 4th ed. (The Johns Hopkins University Press, Baltimore, 2013).
  14. J. Wiersig, Enhancing the Sensitivity of Frequency and Energy Splitting Detection by Using Exceptional Points: Application to Microcavity Sensors for Single-Particle Detection, Phys. Rev. Lett. 112, 203901 (2014).
  15. H.-K. Lau and A. A. Clerk, Fundamental limits and non-reciprocal approaches in non-Hermitian quantum sensing, Nat. Commun. 9, 4320 (2018).
  16. T. E. Lee, F. Reiter, and N. Moiseyev, Entanglement and Spin Squeezing in Non-Hermitian Phase Transitions, Phys. Rev. Lett. 113, 250401 (2014).
  17. Y. Ashida, S. Furukawa, and M. Ueda, Parity-time-symmetric quantum critical phenomena, Nat. Commun. 8, 15791 (2017).
  18. Y. Tserkovnyak, Exceptional points in dissipatively coupled spin dynamics, Phys. Rev. Res. 2, 013031 (2020).
  19. S. Kohler, J. Lehmann, and P. Hänggi, Driven quantum transport on the nanoscale, Phys. Rep. 406, 379 (2005).
  20. S. Datta, Quantum Transport: Atom to Transistor (Cambridge University Press, 2005).
  21. G. Lindblad, On the generators of quantum dynamical semigroups, Commun.Math. Phys. 48, 119 (1976).
  22. V. Gorini, A. Kossakowski, and E. C. G. Sudarshan, Completely positive dynamical semigroups of N-level systems, J. Math. Phys. 17, 821 (1976).
  23. T. Prosen, Third quantization: A general method to solve master equations for quadratic open Fermi systems, New J. Phys. 10, 043026 (2008).
  24. A. McDonald and A. A. Clerk, Third quantization of open quantum systems: Dissipative symmetries and connections to phase-space and Keldysh field-theory formulations, Phys. Rev. Res. 5, 033107 (2023).
  25. A. McDonald, R. Hanai, and A. A. Clerk, Nonequilibrium stationary states of quantum non-Hermitian lattice models, Phys. Rev. B 105, 064302 (2022).
  26. F. Song, S. Yao, and Z. Wang, Non-Hermitian Skin Effect and Chiral Damping in Open Quantum Systems, Phys. Rev. Lett. 123, 170401 (2019).
  27. G. Rickayzen, Green’s Functions and Condensed Matter (Academic Press, 1980).
  28. E. N. Economou, Green’s Functions in Quantum Physics, 3rd ed. (Springer, 2006).
  29. H. Wang, Green’s Function in Condensed Matter Physics, 1st ed. (Alpha Science International, Oxford, UK, 2012).
  30. M. M. Odashima, B. G. Prado, and E. Vernek, Pedagogical introduction to equilibrium Green’s functions: Condensed-matter examples with numerical implementations, Rev. Bras. Ensino Fís. 39, 1 (2016).
  31. J. Cayao and M. Sato, Non-Hermitian phase-biased Josephson junctions, arXiv:2307.15472 (2023).
  32. C.-A. Li, H.-P. Sun, and B. Trauzettel, Anomalous Andreev Spectrum and Transport in Non-Hermitian Josephson Junctions, arXiv:2307.04789 (2024).
  33. V. Kornich, Current-Voltage Characteristics of the Normal Metal-Insulator-PT-Symmetric Non-Hermitian Superconductor Junction as a Probe of Non-Hermitian Formalisms, Phys. Rev. Lett. 131, 116001 (2023).
  34. C. W. J. Beenakker and H. van Houten, The Superconducting Quantum Point Contact, in Nanostructures and Mesoscopic Systems, edited by W. P. Kirk and M. A. Reed (Academic Press, 1992) pp. 481–497.
  35. D. C. Brody, Biorthogonal quantum mechanics, J. Phys. A: Math. Theor. 47, 035305 (2013).
  36. Y. Chen and H. Zhai, Hall conductance of a non-Hermitian Chern insulator, Phys. Rev. B 98, 245130 (2018).
  37. K. Kawabata, T. Numasawa, and S. Ryu, Entanglement Phase Transition Induced by the Non-Hermitian Skin Effect, Phys. Rev. X 13, 021007 (2023).
  38. L. Herviou, N. Regnault, and J. H. Bardarson, Entanglement spectrum and symmetries in non-Hermitian fermionic non-interacting models, SciPost Phys. 7, 069 (2019).
  39. M. Büttiker, Y. Imry, and R. Landauer, Josephson behavior in small normal one-dimensional rings, Phys. Lett. A 96, 365 (1983).
  40. J. P. Carini, K. A. Muttalib, and S. R. Nagel, Origin of the Bohm-Aharonov Effect with Half Flux Quanta, Phys. Rev. Lett. 53, 102 (1984).
  41. N. Byers and C. N. Yang, Theoretical Considerations Concerning Quantized Magnetic Flux in Superconducting Cylinders, Phys. Rev. Lett. 7, 46 (1961).
  42. R. Landauer and M. Büttiker, Resistance of Small Metallic Loops, Phys. Rev. Lett. 54, 2049 (1985).
  43. To maintain a unified formalism across normal rings and SNS junctions, we adopt a constant ΔΔ\Deltaroman_Δ and refrain from self-consistent calculations of observables for SNS junctions.
  44. E. W. Weisstein, Digamma Function (2024a).
  45. E. W. Weisstein, LogGamma Function (2024b).
  46. The source code is available at https://github.com/peixinshen/NonHermitianPersistentCurrentTransport.
  47. In the range of moderate U𝑈Uitalic_U, the current amplitude may fluctuate in normal rings due to the shift of the effective Fermi level.
  48. N. Trivedi and D. A. Browne, Mesoscopic ring in a magnetic field: Reactive and dissipative response, Phys. Rev. B 38, 9581 (1988).
  49. P.-X. Shen, S. Hoffman, and M. Trif, Theory of topological spin Josephson junctions, Phys. Rev. Res. 3, 013003 (2021).
  50. M. Moskalets and M. Büttiker, Floquet scattering theory of quantum pumps, Phys. Rev. B 66, 205320 (2002).
  51. M. Blaauboer, Charge pumping in mesoscopic systems coupled to a superconducting lead, Phys. Rev. B 65, 235318 (2002).
  52. V. F. Becerra, M. Trif, and T. Hyart, Quantized Spin Pumping in Topological Ferromagnetic-Superconducting Nanowires, Phys. Rev. Lett. 130, 237002 (2023).
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