pith. sign in

arxiv: 2605.23250 · v1 · pith:6QY6GQ2Snew · submitted 2026-05-22 · 🪐 quant-ph

A General Quantum Speed Limit for Non-Hermitian Systems

Pith reviewed 2026-05-25 04:43 UTC · model grok-4.3

classification 🪐 quant-ph
keywords quantum speed limitnon-Hermitian systemsbiorthogonal basisMandelstam-Tamm boundMargolus-Levitin boundfastest initial statesopen quantum systems
0
0 comments X

The pith

Two tighter quantum speed limits for non-Hermitian systems are derived from biorthogonal geometry and shown to be attainable.

A machine-rendered reading of the paper's core claim, the machinery that carries it, and where it could break.

The paper establishes two new bounds on the quantum speed limit that apply when a system evolves under a non-Hermitian Hamiltonian. These bounds are constructed by extending the Mandelstam-Tamm and Margolus-Levitin approaches through the use of a complete biorthogonal basis rather than an orthogonal one. The resulting expressions are tighter than prior non-Hermitian proposals and are saturated when the system starts in specially chosen fastest initial states. The work also supplies a practical bound for other initial states and verifies the results on a minimal non-Hermitian example. Readers care because non-Hermitian descriptions are standard for open or PT-symmetric systems where ordinary Hermitian speed limits cannot be used directly.

Core claim

Based on the biorthogonal basis theory we derive two distinct and tighter bounds on the QSL for non-Hermitian systems, which correspond to the MT and ML bounds for Hermitian systems. We show that the shortest evolution time corresponding to the two bounds of the non-Hermitian system can be attained by certain initial states, showing the compactness and tightness of our bounds. These initial states dubbed fastest initial states (FIS) are different from that in Hermitian systems. A bound close to QSL for non-FIS is presented and comparison of our bound with others in literature is performed. To illustrate our results, we present a minimal non-Hermitian system to show QSL, and the condition for

What carries the argument

Biorthogonal basis used to define the time-evolution operator and the geometric quantities that enter the speed-limit expressions.

If this is right

  • The MT-type and ML-type bounds are saturated by distinct fastest initial states (FIS).
  • A separate, looser bound holds for initial states that are not FIS.
  • The new bounds are tighter than earlier non-Hermitian proposals when compared on the same example.
  • An analytic condition for the shortest evolution time is obtained for a minimal non-Hermitian model.

Where Pith is reading between the lines

These are editorial extensions of the paper, not claims the author makes directly.

  • The FIS construction may supply a design principle for preparing states that evolve at the ultimate speed allowed by a given non-Hermitian generator.
  • Because many open-system master equations can be recast as non-Hermitian Schrödinger equations, the bounds could constrain the speed of information processing or decoherence in lossy platforms.
  • If the biorthogonal completeness assumption is relaxed, the same geometric construction might be generalized to defective Hamiltonians that require Jordan blocks.

Load-bearing premise

The non-Hermitian Hamiltonian admits a complete biorthogonal basis that lets the evolution operator and geometric quantities be defined exactly as in the Hermitian case.

What would settle it

Measurement of an evolution time to an orthogonal state in a controlled non-Hermitian system that is shorter than either of the two derived bounds.

Figures

Figures reproduced from arXiv: 2605.23250 by Xiaozhe Hao, X. X. Yi, Zhanxi Wang.

Figure 2
Figure 2. Figure 2: FIG. 2: (a), [PITH_FULL_IMAGE:figures/full_fig_p007_2.png] view at source ↗
Figure 3
Figure 3. Figure 3: FIG. 3 [PITH_FULL_IMAGE:figures/full_fig_p008_3.png] view at source ↗
Figure 4
Figure 4. Figure 4: FIG. 4: Upper and lower bound of the evolution time needed for the [PITH_FULL_IMAGE:figures/full_fig_p008_4.png] view at source ↗
read the original abstract

The quantum speed limit (QSL) refers to the maximum speed of a quantum system to evolve from an initial state to its orthogonal states. The bound on the QSL for Hermitian systems, for example the Mandelstam-Tamm (MT) and Margolus-Levitin (ML) as well as Sun-Zheng(SZ) bound, was studied respectively from the perspectives of average value and variance of the system Hamiltonian as well as the geometry of the system. While the compactness of the MT-type, ML-type and SZ-type bounds has been examined well for Hermitian systems, a compact QSL for non-Hermitian systems has not been well studied. In this work, based on the biorthogonal basis theory we derive two distinct and tighter bounds on the QSL for non-Hermitian systems, which correspond to the MT and ML bounds for Hermitian systems. We show that the shortest evolution time corresponding to the two bounds of the non-Hermitian system can be attained by certain initial states, showing the compactness and tightness of our bounds. These initial states dubbed fastest initial states(FIS) are different from that in Hermitian systems. A bound close to QSL for non-FIS is presented and comparison of our bound with others in literature is performed. To illustrate our results, we present a minimal non-Hermitian system to show QSL, and the condition for the shortest evolution time is derived analytically using the present theory.

Editorial analysis

A structured set of objections, weighed in public.

Desk editor's note, referee report, simulated authors' rebuttal, and a circularity audit. Tearing a paper down is the easy half of reading it; the pith above is the substance, this is the friction.

Referee Report

1 major / 0 minor

Summary. The paper derives two tighter quantum speed limit (QSL) bounds for non-Hermitian systems using biorthogonal basis theory, analogous to the Mandelstam-Tamm (MT) and Margolus-Levitin (ML) bounds for Hermitian systems. It claims these bounds are compact and tight because certain fastest initial states (FIS) attain the minimal evolution time to orthogonality, provides a bound for non-FIS, compares with existing literature, and illustrates with a minimal non-Hermitian example where the condition for shortest time is derived analytically.

Significance. If the derivation holds under its stated assumptions, the work would address an understudied area by extending compact MT- and ML-type QSL bounds to non-Hermitian systems and explicitly constructing attaining states (FIS), with the analytical example providing a concrete test case.

major comments (1)
  1. [Derivation section (opening)] Derivation section (opening paragraphs on biorthogonal expansion): the central construction of the time-evolution operator, overlap, and variance quantities assumes a complete biorthogonal basis of left and right eigenvectors satisfying the biorthogonality relation. This assumption is load-bearing for both the explicit bound formulas and the tightness claim via FIS attainment, yet the manuscript presents the result as general without restricting to diagonalizable Hamiltonians. At exceptional points the algebraic and geometric multiplicities differ, Jordan blocks appear, the basis is incomplete, and the spectral decomposition used does not hold, so the derived bounds and compactness statement do not apply.

Simulated Author's Rebuttal

1 responses · 0 unresolved

We thank the referee for the careful reading and constructive comment. The concern about the scope of the biorthogonal assumption is valid and we address it directly below.

read point-by-point responses
  1. Referee: Derivation section (opening paragraphs on biorthogonal expansion): the central construction of the time-evolution operator, overlap, and variance quantities assumes a complete biorthogonal basis of left and right eigenvectors satisfying the biorthogonality relation. This assumption is load-bearing for both the explicit bound formulas and the tightness claim via FIS attainment, yet the manuscript presents the result as general without restricting to diagonalizable Hamiltonians. At exceptional points the algebraic and geometric multiplicities differ, Jordan blocks appear, the basis is incomplete, and the spectral decomposition used does not hold, so the derived bounds and compactness statement do not apply.

    Authors: We agree that the derivation relies on a complete biorthogonal basis of left and right eigenvectors, which requires the non-Hermitian Hamiltonian to be diagonalizable. The manuscript implicitly adopts this standard assumption of biorthogonal quantum mechanics but does not state it explicitly. The bounds and FIS attainment therefore do not apply at exceptional points. We will revise the manuscript to add an explicit statement of the diagonalizability assumption in the abstract, introduction, and derivation section, together with a brief remark that at exceptional points the spectral decomposition fails and other techniques (e.g., Jordan-form methods) are required. This clarification will be made without altering the technical content of the bounds under the stated assumptions. revision: yes

Circularity Check

0 steps flagged

No circularity; derivation follows from external biorthogonal theory

full rationale

The paper presents its MT- and ML-type bounds for non-Hermitian systems as derived directly from the standard biorthogonal expansion of the time-evolution operator and associated geometric quantities (overlap, variance). No step reduces by construction to a fitted parameter renamed as prediction, a self-defined quantity, or a load-bearing self-citation chain. The completeness assumption for the biorthogonal basis is an explicit modeling choice (not smuggled via citation), and the tightness claim is shown by explicit construction of fastest initial states within that framework. This is the normal case of a self-contained derivation against external benchmarks.

Axiom & Free-Parameter Ledger

0 free parameters · 1 axioms · 0 invented entities

The central claim rests on the standard biorthogonal formalism for non-Hermitian operators; no free parameters, invented entities, or ad-hoc axioms are introduced in the abstract.

axioms (1)
  • domain assumption Non-Hermitian Hamiltonians admit a complete biorthogonal basis allowing definition of time evolution and geometric quantities analogous to the Hermitian case
    Invoked at the start of the derivation to obtain the two bounds

pith-pipeline@v0.9.0 · 5789 in / 1339 out tokens · 21194 ms · 2026-05-25T04:43:44.064041+00:00 · methodology

discussion (0)

Sign in with ORCID, Apple, or X to comment. Anyone can read and Pith papers without signing in.

Reference graph

Works this paper leans on

81 extracted references · 81 canonical work pages

  1. [1]

    Agnew, R

    M. Agnew, R. Eliot, J. Kevin, S. Franke-Arnold, L. Sonja, Jonathan, Discriminating single-photon states unambiguously in high dimensions, Phys. Rev. Lett.113, 020501 (2014)

  2. [2]

    Martinez, E

    D. Martinez, E. S. Gmez, J. Cari ˜ne, L. Pereira, A. Delgado, S. P. Walborn, Certification of a non-projective qudit measurement using multiport beamsplitters, Nat. Phys.19, 190-195 (2023)

  3. [3]

    W. Cai, J. N. Zhang, Z. Hua, W. Wang, X. Pan, X. Liu, Un- ambiguous discrimination of general quantum operations, Sci. Adv.10, eadq2529 (2024)

  4. [4]

    Ashhab, P

    S. Ashhab, P. C. De Groot, F. Nori, Speed limits for quantum gates in multiqubit systems, Phys. Rev. A85, 052327 (2012)

  5. [5]

    Basilewitsch, C

    D. Basilewitsch, C. Dlaska, W. Lechner, Comparing planar quantum computing platforms at the quantum speed limit, Phys. Rev. Res.6, 023026 (2024)

  6. [6]

    H. J. Bremermann, Optimization through evolution and recom- bination, Self-organizing systems93, 106 (1962)

  7. [7]

    H. J. Bremermann, Quantum noise and information, inProc. Fifth Berkeley Symp. Math. Stat. Prob.4, 15-20 (1967)

  8. [8]

    Caneva, M

    T. Caneva, M. Murphy, T. Calarco, R. Fazio, S. Montangero, V . Giovannetti, G. E. Santoro, Optimal control at the quantum speed limit, Phys. Rev. Lett.103, 240501 (2009)

  9. [9]

    Giovannetti, L

    V . Giovannetti, L. Maccone, Sub-Heisenberg estimation strate- gies are ineffective, Phys. Rev. Lett.108, 210404 (2012)

  10. [10]

    Lloyd, Computational capacity of the universe, Phys

    S. Lloyd, Computational capacity of the universe, Phys. Rev. Lett.88, 237901 (2002)

  11. [11]

    Lloyd, Ultimate physical limits to computation, Nature406, 1047-1054 (2000)

    S. Lloyd, Ultimate physical limits to computation, Nature406, 1047-1054 (2000)

  12. [12]

    Deffner, S

    S. Deffner, S. Campbell, Quantum speed limits: from Heisen- berg uncertainty principle to optimal quantum control, J. Phys. A: Math. Theor.50, 453001 (2017)

  13. [13]

    Shanahan, A

    B. Shanahan, A. Chenu, N. Margolus, A. del Campo, Quantum speed limits across the quantum-to-classical transition, Phys. Rev. Lett.120, 070401 (2018)

  14. [14]

    del Campo, I

    A. del Campo, I. L. Egusquiza, M. B. Plenio, S. F. Huelga, Quantum speed limits in open system dynamics, Phys. Rev. Lett.110, 050403 (2013)

  15. [15]

    D. P. Pires, M. Cianciaruso, L. C. C ´eleri, G. Adesso, D. O. Soares-Pinto, Generalized geometric quantum speed limits, Phys. Rev. X6, 021031 (2016)

  16. [16]

    G. Ness, A. Alberti, Y . Sagi, Quantum Speed Limit for States with a Bounded Energy Spectrum, Phys. Rev. Lett.129, 140403 (2022)

  17. [17]

    Uzdin, R

    R. Uzdin, R. Kosloff, Speed limits in Liouville space for open quantum systems, Europhys. Lett.115, 40003 (2016)

  18. [18]

    X. Hu, S. Sun, Y . Zheng, Quantum speed limit via the trajectory ensemble, Phys. Rev. A101, 042107 (2020)

  19. [19]

    Deffner, Geometric quantum speed limits: a case for Wigner phase space, New J

    S. Deffner, Geometric quantum speed limits: a case for Wigner phase space, New J. Phys.19, 103018 (2017)

  20. [20]

    L. P. Garcia-Pintos, A. del Campo, Quantum speed limits under continuous quantum measurements, New J. Phys.21, 033012 (2019)

  21. [21]

    X. M. Zhang, Z. W. Cui, X. Wang, M. H. Yung, Automatic spin- chain learning to explore the quantum speed limit, Phys. Rev. A97, 052333 (2018)

  22. [22]

    S. X. Wu, Y . Zhang, C. S. Yu, H. S. Yi, The initial-state depen- dence of the quantum speed limit, J. Phys. A: Math. Theor.48, 045301 (2014)

  23. [23]

    Bukov, D

    M. Bukov, D. Sels, A. Polkovnikov, Geometric speed limit of accessible many-body state preparation, Phys. Rev. X9, 011034 (2019)

  24. [24]

    Marvian, D

    I. Marvian, D. A. Lidar, Quantum speed limits for leakage and decoherence, Phys. Rev. Lett.115, 210402 (2015)

  25. [25]

    S. Sun, Y . Zheng, Distinct bound of the quantum speed limit via the gauge invariant distance, Phys. Rev. Lett.123, 180403 (2019)

  26. [26]

    Okuyama, M

    M. Okuyama, M. Ohzeki, Quantum speed limit is not quantum, Phys. Rev. Lett.120, 070402 (2018)

  27. [27]

    A. D. Cimmarusti, Z. Yan, B. D. Patterson, L. P. Corcos, P. Lefebvre, L. A. Orozco, S. Deffner, Environment-assisted speed-up of the field evolution in cavity quantum electrodynam- ics, Phys. Rev. Lett.114, 233602 (2015)

  28. [28]

    Fogarty, S

    T. Fogarty, S. Deffner, T. Busch, S. Campbell, Orthogonality catastrophe as a consequence of the quantum speed limit, Phys. Rev. Lett.124, 110601 (2020)

  29. [29]

    Mukhopadhyay, A

    C. Mukhopadhyay, A. Misra, S. Bhattacharya, A. K. Pati, Quantum speed limit constraints on a nanoscale autonomous refrigerator, Phys. Rev. E97, 062116 (2018)

  30. [30]

    Deffner, Quantum speed limits and the maximal rate of in- formation production, Phys

    S. Deffner, Quantum speed limits and the maximal rate of in- formation production, Phys. Rev. Res.2, 013161 (2020)

  31. [31]

    Del Campo, Probing quantum speed limits with ultracold gases, Phys

    A. Del Campo, Probing quantum speed limits with ultracold gases, Phys. Rev. Lett.126, 180603 (2021)

  32. [32]

    Giovannetti, S

    V . Giovannetti, S. Lloyd, L. Maccone, Quantum limits to dy- 10 namical evolution, Phys. Rev. A67, 052109 (2003)

  33. [33]

    C. Liu, Z. Y . Xu, S. Zhu, Quantum-speed-limit time for multi- qubit open systems, Phys. Rev. A91, 022102 (2015)

  34. [34]

    Z. Y . Xu, S. Luo, W. L. Yang, C. Liu, S. Zhu, Quantum speedup in a memory environment, Phys. Rev. A89, 012307 (2014)

  35. [35]

    Deffner, E

    S. Deffner, E. Lutz, Generalized Clausius inequality for nonequilibrium quantum processes, Phys. Rev. Lett.105, 170402 (2010)

  36. [36]

    Hamma, F

    A. Hamma, F. Markopoulou, I. Prmont-Schwarz, S. Severini, Lieb-Robinson Bounds and the Speed of Light from Topologi- cal Order, Phys. Rev. Lett.102, 017204 (2009)

  37. [37]

    L. P. Garcia-Pintos, S. B. Nicholson, J. R. Green, A. Del Campo, A. V . Gorshkov, Unifying quantum and classical speed limits on observables, Phys. Rev. X12, 011038 (2022)

  38. [38]

    Carabba, N

    N. Carabba, N. H ¨ornedal, A. del Campo, Quantum Speed Lim- its on Operator Flows and Correlation Functions, Quantum6, 884 (2022)

  39. [39]

    Mohan, A

    B. Mohan, A. K. Pati, Quantum speed limits for observables, Phys. Rev. A106, 042436 (2022)

  40. [40]

    H ¨ornedal, N

    N. H ¨ornedal, N. Carabba, A. S. Matsoukas-Roubeas, A. del Campo, Ultimate speed limits to the growth of operator com- plexity, Commun. Phys.5, 207 (2022)

  41. [41]

    S. B. Nicholson, A. del Campo, Time-information uncertainty relations in thermodynamics, Nat. Phys.16, 1211-1215 (2020)

  42. [42]

    G. Ness, M. R. Lam, W. Alt, Observing crossover between quantum speed limits, Sci. Adv.7, eabj9119 (2021)

  43. [43]

    Murphy, S

    M. Murphy, S. Montangero, V . Giovannetti, T. Calarco, Com- munication at the Quantum Speed Limit Along a Spin Chain, Phys. Rev. A82, 022318 (2010)

  44. [44]

    Mandelstam, The uncertainty relation between energy and time in nonrelativistic quantum mechanics, J

    L. Mandelstam, The uncertainty relation between energy and time in nonrelativistic quantum mechanics, J. Phys. (USSR)9, 249 (1945)

  45. [45]

    G. N. Fleming, A unitarity bound on the evolution of nonsta- tionary states, Nuovo Cimento A16, 232-240 (1973)

  46. [46]

    Vaidman, Minimum time for the evolution to an orthogonal quantum state, Am

    L. Vaidman, Minimum time for the evolution to an orthogonal quantum state, Am. J. Phys.60, 182-183 (1992)

  47. [47]

    Anandan, Y

    J. Anandan, Y . Aharonov, Geometry of quantum evolution, Phys. Rev. Lett.65, 1697 (1990)

  48. [48]

    Margolus, L

    N. Margolus, L. B. Levitin, The maximum speed of dynamical evolution, Physica D120, 188-195 (1998)

  49. [49]

    Minganti, A

    F. Minganti, A. Miranowicz, R. W. Chhajlany, F. Nori, Quan- tum exceptional points of non-Hermitian Hamiltonians and Li- ouvillians: The effects of quantum jumps, Phys. Rev. A100, 062131 (2019)

  50. [50]

    Ashida, Z

    Y . Ashida, Z. Gong, M. Ueda, Non-hermitian physics, Adv. Phys.69, 249-435 (2020)

  51. [51]

    C. M. Bender, Making sense of non-Hermitian Hamiltonians, Rep. Prog. Phys.70, 947 (2007)

  52. [52]

    Roccati, G

    F. Roccati, G. M. Palma, F. Ciccarello, F. Ciccarello, Non- Hermitian physics and master equations, Open Syst. Inf. Dyn. 29, 2250004 (2022)

  53. [53]

    Mostafazadeh, Pseudo-Hermiticity versus PT-symmetry III: Equivalence of pseudo-Hermiticity and the presence of antilin- ear symmetries, J

    A. Mostafazadeh, Pseudo-Hermiticity versus PT-symmetry III: Equivalence of pseudo-Hermiticity and the presence of antilin- ear symmetries, J. Math. Phys.43, 3944-3951 (2002)

  54. [54]

    C. M. Bender, D. C. Brody, H. F. Jones, Complex Extension of Quantum Mechanics, Phys. Rev. Lett.89, 270401 (2002)

  55. [55]

    H. J. Carmichael, Quantum trajectory theory for cascaded open systems, Phys. Rev. Lett.70, 2273 (1993)

  56. [56]

    Deffner, E

    S. Deffner, E. Lutz, Quantum speed limit for non-Markovian dynamics, Physical Review Letters111, 010402 (2013)

  57. [57]

    Campaioli, F

    F. Campaioli, F. A. Pollock, F. C. Binder, K. Modi, Tighten- ing quantum speed limits for almost all states, Physical Review Letters120, 060409 (2018)

  58. [58]

    Cao, S.P

    K. Cao, S.P. Kou, Statistical mechanics for non-Hermitian quantum systems, Physical Review Research5, 033196 (2023)

  59. [59]

    S. Sun, Y . Peng, X. Hu, Y . Zheng, Quantum speed limit quan- tified by the changing rate of phase, Physical Review Letters 127, 100404 (2021)

  60. [60]

    X. D. Cui, Y . Zheng, Geometric phases in non-Hermitian quan- tum mechanics, Phys. Rev. A86, 064104 (2012)

  61. [61]

    Srivastav, V

    A. Srivastav, V . Pandey, B. Mohan, A. K. Pati, Family of exact and inexact quantum speed limits for completely positive and trace-preserving dynamics, arXiv preprint arXiv:2406.08584 (2024)

  62. [62]

    Hasegawa, Unifying speed limit, thermodynamic uncertainty relation and Heisenberg principle via bulk-boundary correspon- dence, Nature Communications14, 2828 (2023)

    Y . Hasegawa, Unifying speed limit, thermodynamic uncertainty relation and Heisenberg principle via bulk-boundary correspon- dence, Nature Communications14, 2828 (2023)

  63. [63]

    Yadin, Quantum Speed Limit for States and Observables of Perturbed Open Systems, Phys

    B. Yadin, Quantum Speed Limit for States and Observables of Perturbed Open Systems, Phys. Rev. Lett.132, 230404 (2024)

  64. [64]

    Y . J. Zhang, W. Han, Y . J. Xia, J. P. Cao, H. Fan, Classical- driving-assisted quantum speed-up, Physical Review A91, 032112 (2015)

  65. [65]

    H. B. Liu, W. L. Yang, J. H. An, Z. Y . Xu, Mechanism for Quantum Speedup in Open Quantum Systems, Phys. Rev. A 93, 020105 (2016)

  66. [66]

    Weidemann, M

    S. Weidemann, M. Kremer, S. Longhi, A. Szameit, Coexistence of dynamical delocalization and spectral localization through stochastic dissipation, Nature Photonics15, 576-581 (2021)

  67. [67]

    Impens, F

    F. Impens, F. M. dAngelis, F. A. Pinheiro, D. Gu ´ery-Odelin, Time scaling and quantum speed limit in non-Hermitian Hamil- tonians, Phys. Rev. A104, 052620 (2021)

  68. [68]

    Campaioli, F

    F. Campaioli, F. A. Pollock, K. Modi, Tight, robust, and feasi- ble quantum speed limits for open dynamics, Quantum3, 168 (2019)

  69. [69]

    Wong, Results on certain non-Hermitian Hamiltonians, Jour- nal of Mathematical Physics8, 2039-2042 (1967)

    J. Wong, Results on certain non-Hermitian Hamiltonians, Jour- nal of Mathematical Physics8, 2039-2042 (1967)

  70. [70]

    Y . Jing, J. J. Dong, Y . Y . Zhang, Z. X. Hu, Biorthogonal dy- namical quantum phase transitions in non-Hermitian systems, Physical Review Letters132, 220402 (2024)

  71. [71]

    G. Sun, J. C. Tang, S. P. Kou, Biorthogonal quantum criticality in non-Hermitian many-body systems, Frontiers of Physics17, 1-9 (2022)

  72. [72]

    A. Mostafazadeh, Pseudo-Hermiticity versus PT symmetry: The necessary condition for the reality of the spectrum of a non-Hermitian Hamiltonian, Journal of Mathematical Physics 43, 205-214 (2002)

  73. [73]

    D. C. Brody, Biorthogonal quantum mechanics, J. Phys. A: Math. Theor.47, 035305 (2013)

  74. [74]

    L. B. Levitin, T. Toffoli, Fundamental limit on the rate of quan- tum dynamics: the unified bound is tight, Phys. Rev. Lett.103, 160502 (2009)

  75. [75]

    Y . Wu, L. Kang, D. H. Werner, Generalized PT symmetry in non-Hermitian wireless power transfer systems, Phys. Rev. Lett.129, 200201 (2022)

  76. [76]

    X. Hao, K. Yin, J. Zou, R. Wang, Y . Huang, X. Ma, T. Dong, Frequency-Stable Robust Wireless Power Transfer Based on High-Order Pseudo-Hermitian Physics, Phys. Rev. Lett.130, 077202 (2023)

  77. [77]

    C. M. Bender, S. Boettcher, Real spectra in non-Hermitian Hamiltonians having PT symmetry, Phys. Rev. Lett.80, 5243 (1998)

  78. [78]

    Dorey, C

    P. Dorey, C. Dunning, R. Tateo, Spectral equivalences, Bethe ansatz equations, and reality properties in PT-symmetric quan- tum mechanics, J. Phys. A: Math. Gen.34, 5679 (2001)

  79. [79]

    M. V . Berry, Physics of nonhermitian degeneracies, Czechoslov. J. Phys.54, 1039-1047 (2004)

  80. [80]

    W. D. Heiss, The physics of exceptional points, J. Phys. A: Math. Theor.45, 444016 (2012). 11

Showing first 80 references.