Analytical diagonalisation of the Hamiltonian of the quantum Rabi model in the Coulomb gauge

Authors

  • Aliaksandr U. Leonau Belarusian State University, 4 Niezaliežnasci Avenue, Minsk 220030, Belarus
  • Ilya D. Feranchuk Belarusian State University, 4 Niezaliežnasci Avenue, Minsk 220030, Belarus

Keywords:

quantum Rabi model, operator method, two-level system, quantum field, resonance, gauge invariance

Abstract

In the present paper we investigate the approximate analytical diagonalisation of the Hamiltonian of the quantum Rabi model written in the Coulomb gauge and taking into account the gauge invariance of the system. It is shown that the Hamiltonian of the model can be diagonalised with high accuracy on the basis of a unitary operator of the gauge transformation utilising a simple basis set of state vectors. It is essential that the obtained approximate expressions do not depend on the variational parameters and are valid within the whole range of the parameter values. The zeroth-order approximation and uniformly available approximation are derived for the eigenstates of the system, and their comparison with the results of the numerical simulation is elaborated. The second-order correction to the zeroth-order approximation is deduced and its contribution to the energy of the system is estimated. The obtained results could be useful for description of the evolution of the quantum Rabi model as well as for investigation of systems of two-level atoms in the resonant quantum field.

Author Biographies

  • Aliaksandr U. Leonau, Belarusian State University, 4 Niezaliežnasci Avenue, Minsk 220030, Belarus

    PhD (physics and mathematics), docent; associate professor at the department of theoretical physics and astrophysics, faculty of physics

  • Ilya D. Feranchuk, Belarusian State University, 4 Niezaliežnasci Avenue, Minsk 220030, Belarus

    doctor of science (physics and mathematics), full professor; professor at the department of theoretical physics and astrophysics, faculty of physics

References

  1. Rabi II. On the process of space quantization. Physical Review. 1936;49(4):324–328. DOI: 10.1103/PhysRev.49.324.
  2. Rabi II. Space quantization in a gyrating magnetic field. Physical Review. 1937;51(8):652–654. DOI: 10.1103/PhysRev.51.652.
  3. Walther H, Varcoe BTH, Englert B-G, Becker T. Cavity quantum electrodynamics. Reports on Progress in Physics. 2006;69(5):1325–1382. DOI: 10.1088/0034-4885/69/5/R02.
  4. Raimond JM, Brune M, Haroche S. Manipulating quantum entanglement with atoms and photons in a cavity. Reviews of Modern Physics. 2001;73(3):565–582. DOI: 10.1103/RevModPhys.73.565.
  5. HolsteinT. Studies of polaron motion: partI. The molecular-crystal model. Annals of Physics. 1959;8(3):325–342. DOI: 10.1016/0003-4916(59)90002-8.
  6. Feranchuk ID, Leonov AV, Skoromnik OD. Physical background for parameters of the quantum Rabi model. Journal of Physics A: Mathematical and Theoretical. 2016;49(45):454001. DOI: 10.1088/1751-8113/49/45/454001.
  7. Kockum AF, Miranowicz A, Macrì V, Savasta S, Nori F. Deterministic quantum nonlinear optics with single atoms and virtual photons. Physical Review A: Covering Atomic, Molecular, and Optical Physics and Quantum Information. 2017;95(6):063849. DOI: 10.1103/PhysRevA.95.063849.
  8. Felicetti S, Rossatto DZ, Rico E, Solano E, Forn-Díaz P. Two-photon quantum Rabi model with superconducting circuits. Physical Review A: Covering Atomic, Molecular, and Optical Physics and Quantum Information. 2018;97(1):013851. DOI: 10.1103/PhysRevA.97.013851.
  9. Stassi R, Macrì V, KockumAF, Di Stefano O, MiranowiczA, Savasta S, et al. Quantum nonlinear optics without photons. Physical Review A: Covering Atomic, Molecular, and Optical Physics and Quantum Information. 2017;96(2):023818. DOI: 10.1103/PhysRevA.96.023818.
  10. Forn-Díaz P, Lamata L, Rico E, Kono J, Solano E. Ultrastrong coupling regimes of light-matter interaction. Reviews of Modern Physics. 2019;91(2):025005. DOI: 10.1103/RevModPhys.91.025005.
  11. Braak D. Integrability of the Rabi model. Physical Review Letters. 2011;107(10):100401. DOI: 10.1103/PhysRevLett.107.100401.
  12. Feranchuk ID, Komarov LI, Ulyanenkov AP. Two-level system in a one-mode quantum field: numerical solution on the basis of the operator method. Journal of Physics A: Mathematical and General. 1996;29(14):4035–4047. DOI: 10.1088/0305-4470/29/14/026.
  13. Irish EK. Generalized rotating-wave approximation for arbitrarily large coupling. Physical Review Letters. 2007;99(17):173601. DOI: 10.1103/PhysRevLett.99.173601.
  14. Yu-Yu Zhang, Qing-Hu Chen, Yang Zhao. Generalized rotating-wave approximation to biased qubit-oscillator systems. Physical Review A: Covering Atomic, Molecular, and Optical Physics and Quantum Information. 2013;87(3):033827. DOI: 10.1103/PhysRevA.87.033827.
  15. Zi-Min Li, Batchelor MT. Generalized adiabatic approximation to the quantum Rabi model. Physical Review A: Covering Atomic, Molecular, and Optical Physics and Quantum Information. 2021;104(3):033712. DOI: 10.1103/PhysRevA.104.033712.
  16. Di Stefano O, Settineri A, Macrì V, Garziano L, Stassi R, Savasta S, et al. Resolution of gauge ambiguities in ultrastrong-coupling cavity quantum electrodynamics. Nature Physics. 2019;15(8):803–808. DOI: 10.1038/s41567-019-0534-4.
  17. Feranchuk I, Ivanov A, Van-Hoang Le, Ulyanenkov A. Non-perturbative description of quantum systems. Cham: Springer International Publishing; 2015. xv, 362 p. (Lecture notes in physics; volume 894). DOI: 10.1007/978-3-319-13006-4.
  18. Scully MO, Zubairy MS. Quantum optics. Cambridge: Cambridge University Press; 1997. xxi, 630 p. DOI: 10.1017/CBO9780511813993.
  19. Jaynes ET, Cummings FW. Comparison of quantum and semiclassical radiation theories with application to the beam maser. Proceedings of the IEEE. 1963;51(1):89–109. DOI: 10.1109/PROC.1963.1664.
  20. Leonau А, Feranchuk I. Dvukhurovnevaya sistema v odnomodovom kvantovom pole [Two-level system in a single-mode quantum field]. Saarbrücken: Lambert Academic Publishing; 2011. 116 p. Russian.
  21. Leonau AU. Investigating the convergence of the iteration scheme of operator method for description of eigenstates of the quantum Rabi model. Journal of the Belarusian State University. Physics. 2018;3:74–80. Russian.

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Published

2022-01-27

How to Cite

(1)
Leonau, A. U.; Feranchuk, I. D. . Analytical Diagonalisation of the Hamiltonian of the Quantum Rabi Model in the Coulomb Gauge. Журнал Белорусского государственного университета. Физика 2022, No. 1, 44-51. https://doi.org/10.33581/2520-2243-2022-1-44-51.