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Symdyn: An automated algebraic solution for high-order quantum systems

D. Martínez-Tibaduiza1,*, Vladimir Vargas-Calderón2, J. G. Dueñas3, J. Flórez-Jiménez4, and A. Z. Khoury1

  • 1Instituto de Física, Universidade Federal Fluminense, Avenida Litorânea, 24210-346 Niteroi, RJ, Brazil
  • 2D-Wave Systems Inc., Burnaby, British Columbia, Canada
  • 3Information Analysis Group, Special Jurisdiction for Peace, Cra 7 No 63-44, Bogotá, Colombia
  • 4Lyric, Sunnyvale, California 94087, USA

  • *Contact author: danielmartinezt@gmail.com

Phys. Rev. Research 8, 013078 – Published 26 January, 2026

DOI: https://doi.org/10.1103/24r3-j9zy

Abstract

Many important quantum systems are characterized by Hamiltonians expressible as a linear combination of time-independent generators of a finite Lie algebra, Ĥ(t)=∑l=1Lηl(t)ĝl. The Wei-Norman framework provides a powerful analytical method for computing the exact time-evolution operator in a factorized form, Û(t)=∏l=1LeΛl(t)ĝl. By exploiting the underlying algebraic structure, the method yields a system of differential equations—the Wei-Norman equations—which determine the time-evolution operator coefficients Λl(t) from the Hamiltonian ones ηl(t). Although robust and formally extendable, applying the method by hand becomes increasingly difficult or even intractable for high-order systems (L≥6). In this work, we introduce symdyn, a Python library that automates the application of this method. Given the commutators between generators, the library symbolically derives the Wei-Norman equations and efficiently computes nested commutators, similarity transformations, and the differential equations that yield Baker-Campbell-Hausdorff-like relations. We validate the library by recovering known results for quantum systems associated with the Lie algebras su(1,1), su(2), sl(2), and so(2,1), and further demonstrate its capabilities by deriving the Wei-Norman equations for a system of two coupled time-dependent harmonic oscillators involving 11 generators. Additionally, we specialize the library to handle the Lie group SU(N) using a generic Cartan-Weyl basis for its algebra, and demonstrate its versatility by deriving the Wei-Norman equations for su(2), su(3), and su(4), including the explicit construction of a set of quantum gates for universal quantum computation.

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References (117)

  1. J. J. Sakurai and J. Napolitano, Modern Quantum Mechanics (Pearson, Harlow, 2014).
  2. W. Magnus, On the exponential solution of differential equations for a linear operator, Commun. Pure Appl. Math. 7, 649 (1954).
  3. S. Blanes, F. Casas, J. A. Oteo, and J. Ros, The magnus expansion and some of its applications, Phys. Rep. 470, 151 (2009).
  4. J. Wei and E. Norman, Lie algebraic solution of linear differential equations, J. Math. Phys. 4, 575 (1963).
  5. J. Wei and E. Norman, On global representations of the solutions of linear differential equations as a product of exponentials, Proc. Am. Math. Soc. 15, 327 (1964).
  6. S. Charzyński and M. Kuś, Wei–Norman equations for a unitary evolution, J. Phys. A: Math. Theor. 46, 265208 (2013).
  7. S. Charzyński and M. Kuś, Wei–Norman equations for classical groups, J. Diff. Equ. 259, 1542 (2015).
  8. R. W. Brockett, System theory on group manifolds and coset spaces, SIAM J. Control 10, 265 (1972).
  9. R. W. Brockett, Lie Algebras and Lie Groups in Control Theory (Springer, Netherlands, 1973), pp. 43–82.
  10. A. M. Bloch, Nonholonomic mechanics, in Nonholonomic Mechanics and Control, edited by S. S. Antman, L. Greengard, and P. Holmes (Springer, New York, 2015), pp. 235–313.
  11. R. M. Wilcox, Exponential operators and parameter differentiation in quantum physics, J. Math. Phys. 8, 962 (1967).
  12. F. Dell’Anno, S. De Siena, and F. Illuminati, Multiphoton quantum optics and quantum state engineering, Phys. Rep. 428, 53 (2006).
  13. J. F. Cariñena, A. Ibort, G. Marmo, and G. Morandi, Geometry from Dynamics, Classical and Quantum (Springer, Netherlands, 2015).
  14. R. Kosloff and Y. Rezek, The quantum harmonic Otto cycle, Entropy 19, 136 (2017).
  15. S. Qvarfort, M. R. Vanner, P. F. Barker, and D. E. Bruschi, Master-equation treatment of nonlinear optomechanical systems with optical loss, Phys. Rev. A 104, 013501 (2021).
  16. A. C. Duriez, D. Martínez-Tibaduiza, and A. Z. Khoury, Algebraic approach to a nonadiabatic coupled Otto cycle, Phys. Rev. A 106, 062212 (2022).
  17. S. Qvarfort and I. Pikovski, Solving quantum dynamics with a Lie-algebra decoupling method, PRX Quantum 6, 010201 (2025).
  18. L. Šnob and P. Winternitz, Classification and Identification of Lie Algebras (American Mathematical Society, Providence, Rhode Island, USA, 2017), Vol. 33.
  19. R. Lecamwasam, T. Iakovleva, and J. Twamley, Quantum metrology with linear Lie algebra, Phys. Rev. Res. 6, 043137 (2024).
  20. N. Hatano and M. Suzuki, Finding Exponential Product Formulas of Higher Orders (Springer, Berlin, 2005), pp. 37–68.
  21. L. Teuber and S. Scheel, Solving the quantum master equation of coupled harmonic oscillators with Lie-algebra methods, Phys. Rev. A 101, 042124 (2020).
  22. D. Martínez-Tibaduiza, C. González-Arciniegas, C. Farina, A. Cavalcanti-Duriez, and A. Z. Khoury, Quantum-based solution of time-dependent complex Riccati equations, Phys. Rev. A 107, 042211 (2023).
  23. I. Ramos-Prieto, R. Román-Ancheyta, J. Récamier, and H. M. Moya-Cessa, Exact solution of a non-stationary cavity with one intermode interaction, J. Opt. Soc. Am. B 38, 2873 (2021).
  24. The original BCH formula can be straightforwardly deduced using the BCH lemma as eĝieĝj=exp[ĝi+∫01dθeθĝiĝje−θĝi].
  25. S. Barnett and P. M. Radmore, Methods in Theoretical Quantum Optics (Oxford University Press, 2002).
  26. C. Altafini, Explicit Wei–Norman for matrix Lie groups via Putzer's method, Syst. Control Lett. 54, 1121 (2005).
  27. R. Gilmore, Baker-Campbell-Hausdorff formulas, J. Math. Phys. 15, 2090 (1974).
  28. More generally, we have that (adĝn)⋯(adĝk)(adĝi)ĝj=∑l=1L(Υn⋯ΥkΥi)jlĝl. This result could be useful to automate the construction of exact effective Hamiltonians [29].
  29. A. Chakraborty, T. L. Patti, B. Khailany, A. N. Jordan, and A. Anandkumar, GPU-accelerated effective Hamiltonian calculator, Quantum 9, 1946 (2025).
  30. L. E. de Clercq, et al., Estimation of a general time-dependent Hamiltonian for a single qubit, Nat. Commun. 7, 11218 (2016).
  31. K. Husimi, Miscellanea in elementary quantum mechanics, II, Prog. Theor. Phys. 9, 381 (1953).
  32. D. M. Tibaduiza, L. Pires, A. L. C. Rego, D. Szilard, C. Zarro, and C. Farina, Efficient algebraic solution for a time-dependent quantum harmonic oscillator, Phys. Scr. 95, 105102 (2020).
  33. D. Martínez-Tibaduiza, L. Pires, and C. Farina, Time-dependent quantum harmonic oscillator: A continuous route from adiabatic to sudden changes, J. Phys. B: At. Mol. Opt. Phys. 54, 205401 (2021).
  34. C. D. Ahlbrandt and A. C. Peterson, Discrete Hamiltonian Systems (Springer, 1996).
  35. J.-S. Li and N. Khaneja, Ensemble control of Bloch equations, IEEE Trans. Autom. Control 54, 528 (2009).
  36. D. E. Bruschi and A. Xuereb, “Mechano-optics”: An optomechanical quantum simulator, New J. Phys. 20, 065004 (2018).
  37. D. E. Bruschi, Time evolution of coupled multimode and multiresonator optomechanical systems, J. Math. Phys. 60, 062105 (2019).
  38. S. Qvarfort, A. Serafini, A. Xuereb, D. Rätzel, and D. E. Bruschi, Enhanced continuous generation of non-Gaussianity through optomechanical modulation, New J. Phys. 21, 055004 (2019).
  39. C. Elouard, D. Herrera-Martí, M. Esposito, and A. Auffèves, Thermodynamics of optical Bloch equations, New J. Phys. 22, 103039 (2020).
  40. R. Dann, R. Kosloff, and P. Salamon, Quantum finite-time thermodynamics: Insight from a single qubit engine, Entropy 22, 1255 (2020).
  41. L. Dupays and A. Chenu, Shortcuts to squeezed thermal states, Quantum, 5, 449 (2021).
  42. O. Abah, G. De Chiara, M. Paternostro, and R. Puebla, Harnessing nonadiabatic excitations promoted by a quantum critical point: Quantum battery and spin squeezing, Phys. Rev. Res. 4, L022017 (2022).
  43. B. M. Mihalcea, Quasienergy operators and generalized squeezed states for systems of trapped ions, Ann. Phys. 442, 168926 (2022).
  44. Z. Fei and C. P. Sun, Many-body systems with SU(1, 1) dynamical symmetry: From dynamics to thermodynamics based on the trace formula, arXiv:2111.11041.
  45. C. C. Rusconi, M. Perdriat, G. Hétet, O. Romero-Isart, and B. A. Stickler, Spin-controlled quantum interference of levitated nanorotors, Phys. Rev. Lett. 129, 093605 (2022).
  46. D. F. Walls, Squeezed states of light, Nature (London) 306, 141 (1983).
  47. J. Ma, X. Wang, C. P. Sun, and F. Nori, Quantum spin squeezing, Phys. Rep. 509, 89 (2011).
  48. M. S. Silver, R. I. Joseph, and D. I. Hoult, Selective spin inversion in nuclear magnetic resonance and coherent optics through an exact solution of the Bloch-Riccati equation, Phys. Rev. A 31, 2753 (1985).
  49. R. A. de Graaf, In Vivo NMR Spectroscopy: Principles and Techniques (John Wiley & Sons, 2019).
  50. J.-Q. Shen, H.-Y. Zhu, and P. Chen, Exact solutions and geometric phase factor of time-dependent three-generator quantum systems, Eur. Phys. J. D 23, 305 (2003).
  51. A. Laufer, The exponential map of GL(N), J. Phys. A: Math. Gen. 30, 5455 (1997).
  52. J. Bradbury, R. Frostig, P. Hawkins, M. J. Johnson, C. Leary, D. Maclaurin, G. Necula, A. Paszke, J. VanderPlas, S. Wanderman-Milne, and Q. Zhang, JAX: Composable transformations of Python NumPy programs, GitHub, 2018, http://github.com/google/jax.
  53. A. Paszke, et al., Pytorch: An imperative style, high-performance deep learning library (2019).
  54. A. Meurer, et al., Sympy: Symbolic computing in Python, PeerJ Comput. Sci. 3, e103 (2017).
  55. The name “block-decoupled” signals that some of the resulting differential equations for high-order QLSs will still be coupled, but in blocks with the maximum size of the algebra rank (maximum number of diagonalizable matrices), as we will see in Secs.  3a and 4.
  56. P.-Y. Tsai and C.-K. Chen, An approximate analytic solution of the nonlinear Riccati differential equation, J. Franklin Inst. 347, 1850 (2010).
  57. C. Altafini, Parameter differentiation and quantum state decomposition for time varying Schrödinger equations, Rep. Math. Phys. 52, 381 (2003).
  58. A. Das and S. Okubo, Lie Groups and Lie Algebras for Physicists (World Scientific, 2014).
  59. D. H. Sattinger and O. L. Weaver, Lie Groups and Algebras with Applications to Physics, Geometry, and Mechanics, Applied Mathematical Sciences (Springer-Verlag, New York, 1986).
  60. B. C. Hall, Lie Groups, Lie Algebras, and Representations: An Elementary Introduction (Springer International Publishing, Switzerland, 2015).
  61. D. P. DiVincenzo, Two-bit gates are universal for quantum computation, Phys. Rev. A 51, 1015 (1995).
  62. A. Barenco, C. H. Bennett, R. Cleve, D. P. DiVincenzo, N. Margolus, P. Shor, T. Sleator, J. A. Smolin, and H. Weinfurter, Elementary gates for quantum computation, Phys. Rev. A 52, 3457 (1995).
  63. J. A. Bergou, M. Hillery, and M. Saffman, Quantum Information Processing: Theory and Implementation (Springer International Publishing, 2021).
  64. D. A. Steck, Quantum and Atom Optics, available online at http://steck.us/teaching (revision 0.16.6, 17 October 2025).
  65. https://gitlab.com/VolodyaCO/dynamics-of-sun-systems.
  66. R. Loudon and P. L. Knight, Squeezed light, J. Mod. Opt. 34, 709 (1987).
  67. L. A. Wu, M. Xiao, and H. J. Kimble, Squeezed states of light from an optical parametric oscillator, J. Opt. Soc. Am. B 4, 1465 (1987).
  68. M. C. Teich and B. E. A. Saleh, Squeezed state of light, Quantum Opt. 1, 153 (1989).
  69. L. P. Grishchuk and Y. V. Sidorov, Squeezed quantum states of relic gravitons and primordial density fluctuations, Phys. Rev. D 42, 3413 (1990).
  70. C. F. Lo, Time evolution of scalar field in spatially flat Robertson-Walker space-time, Phys. Scr. 44, 217 (1991).
  71. J. Perina, Quantum Statistics of Linear and Nonlinear Optical Phenomena (Springer Science & Business Media, 1991).
  72. L. P. Grishchuk, Quantum effects in cosmology, Class. Quantum Grav. 10, 2449 (1993).
  73. A. Albrecht, P. Ferreira, M. Joyce, and T. Prokopec, Inflation and squeezed quantum states, Phys. Rev. D 50, 4807 (1994).
  74. B. L. Hu, G. Kang, and A. Matacz, Squeezed vacua and the quantum statistics of cosmological particle creation, Int. J. Mod. Phys. A 09, 991 (1994).
  75. V. V. Dodonov, “Nonclassical” states in quantum optics: A “squeezed” review of the first 75 years, J. Opt. B: Quantum Semiclass. Opt. 4, R1 (2002).
  76. V. V. Dodonov and V. I. Man'ko, Theory of Nonclassical States of Light (CRC Press, 2003).
  77. M. B. Einhorn and F. Larsen, Squeezed states in the de Sitter vacuum, Phys. Rev. D 68, 064002 (2003).
  78. V. V. Dodonov and A. V. Dodonov, Quantum harmonic oscillator and nonstationary Casimir effect, J. Russ. Las. Res. 26, 445 (2005).
  79. T. Fujii, S. Matsuo, N. Hatakenaka, S. Kurihara, and A. Zeilinger, Quantum circuit analog of the dynamical Casimir effect, Phys. Rev. B 84, 174521 (2011).
  80. P. Lähteenmäki, G. S. Paraoanu, J. Hassel, and P. J. Hakonen, Dynamical Casimir effect in a Josephson metamaterial, Proc. Natl. Acad. Sci. USA 110, 4234 (2013).
  81. S. Felicetti, M. Sanz, L. Lamata, G. Romero, G. Johansson, P. Delsing, and E. Solano, Dynamical Casimir effect entangles artificial atoms, Phys. Rev. Lett. 113, 093602 (2014).
  82. R. Schnabel, Squeezed states of light and their applications in laser interferometers, Phys. Rep. 684, 1 (2017).
  83. F. A. Raffa, M. Rasetti, and M. Genovese, New quantumness domains through generalized squeezed states, J. Phys. A: Math. Theor. 52, 475301 (2019).
  84. I. D Leroux, M. H Schleier-Smith, and V. Vuletić, Implementation of cavity squeezing of a collective atomic spin, Phys. Rev. Lett. 104, 073602 (2010).
  85. O. Hosten, N. J. Engelsen, R. Krishnakumar, and M. A. Kasevich, Measurement noise 100 times lower than the quantum-projection limit using entangled atoms, Nature (London) 529, 505 (2016).
  86. H. Bao, et al., Spin squeezing of 1011 atoms by prediction and retrodiction measurements, Nature (London) 581, 159 (2020).
  87. H. Vahlbruch, S. Chelkowski, K. Danzmann, and R. Schnabel, Quantum engineering of squeezed states for quantum communication and metrology, New J. Phys. 9, 371 (2007).
  88. V. Giovannetti, S. Lloyd, and L. Maccone, Advances in quantum metrology, Nat. Photon. 5, 222 (2011).
  89. R. Slavík, et al., All-optical phase and amplitude regenerator for next-generation telecommunications systems, Nat. Photon. 4, 690 (2010).
  90. K. G. Fedorov, et al., Displacement of propagating squeezed microwave states, Phys. Rev. Lett. 117, 020502 (2016).
  91. S. Pogorzalek, et al., Secure quantum remote state preparation of squeezed microwave states, Nat. Commun. 10, 2604 (2019).
  92. L. Barsotti, J. Harms, and R. Schnabel, Squeezed vacuum states of light for gravitational wave detectors, Rep. Prog. Phys. 82, 016905 (2019).
  93. M. Tse, et al., Quantum-enhanced advanced LIGO detectors in the era of gravitational-wave astronomy, Phys. Rev. Lett. 123, 231107 (2019).
  94. W. Jia, V. Xu, K. Kuns, M. Nakano, and members of the LIGO Scientific Collaboration, Squeezing the quantum noise of a gravitational-wave detector below the standard quantum limit, Science 385, 1318 (2024).
  95. F. Wolf and H. J. Korsch, Time-evolution operators for (coupled) time-dependent oscillators and Lie algebraic structure theory, Phys. Rev. A 37, 1934 (1988).
  96. C. K. Law, Effective hamiltonian for the radiation in a cavity with a moving mirror and a time-varying dielectric medium, Phys. Rev. A 49, 433 (1994).
  97. Note that this type of calculation allows to obtain changes of basis or the time evolution of any Lie vector within the Heisenberg picture. More generally, for suitable well-behaved functions of the generators f(ĝj), we have that (eΛiadĝi)f(ĝj)=f((eΛiadĝi)ĝj) [25].
  98. W. Pfeifer, The Lie Algebras Su(n) (Birkhäuser, Basel, 2003).
  99. P. Skands, Introduction to QCD, in Searching for New Physics at Small and Large Scales (World Scientific, 2013).
  100. H. Georgi and S. L. Glashow, Unity of all elementary-particle forces, Phys. Rev. Lett. 32, 438 (1974).
  101. M. A. Nielsen and I. L. Chuang, Quantum Computation and Quantum Information: 10th Anniversary Edition (Cambridge University Press, 2012).
  102. R. Wiersema, D. Lewis, D. Wierichs, J. Carrasquilla, and N. Killoran, Here comes the su(n): Multivariate quantum gates and gradients, Quantum, 8, 1275 (2024).
  103. C. M. Caves and G. J. Milburn, Qutrit entanglement, Opt. Commun. 179, 439 (2000).
  104. A. B. Klimov, R. Guzmán, J. C. Retamal, and C. Saavedra, Qutrit quantum computer with trapped ions, Phys. Rev. A 67, 062313 (2003).
  105. P. Gokhale, J. M. Baker, C. Duckering, N. C. Brown, K. R. Brown, and F. T. Chong, Asymptotic improvements to quantum circuits via qutrits, in Proceedings of the 46th International Symposium on Computer Architecture, ISCA'19 (ACM Press, New York, NY, 2019), pp. 554–566.
  106. Y. Wang, Z. Hu, B. C. Sanders, and S. Kais, Qudits and high-dimensional quantum computing, Front. Phys. 8, 589504 (2020).
  107. In case the inserted matrices do not close a Lie algebra, the user will be notified by the library.
  108. G. Dattoli, P. Di Lazzaro, and A. Torre, Su(1, 1), su(2), and su(3) coherence-preserving Hamiltonians and time-ordering techniques, Phys. Rev. A 35, 1582 (1987).
  109. M. F. Cavalcante, B. Çakmak, M. V. S. Bonança, and S. Deffner, Correcting noisy quantum gates with shortcuts to adiabaticity, Europhys. Lett. 152, 48001 (2025).
  110. Macbook Pro, Apple M1 Max chip, 32 GB RAM.
  111. F. M. Surace, P. Fromholz, F. Scazza, and M. Dalmonte, Scalable ab initio protocol for quantum simulating SU(N)×U(1) lattice gauge theories, Quantum 8, 1359 (2024).
  112. R. Cestnik and E. A. Martens, Integrability of a globally coupled complex Riccati array: Quadratic integrate-and-fire neurons, phase oscillators, and all in between, Phys. Rev. Lett. 132, 057201 (2024).
  113. M. A. Lohe, Exact reduction of synchronized systems in higher-dimensional spaces, Chaos 35, 023144 (2025).
  114. A. Di Meglio, et al., Quantum computing for high-energy physics: State of the art and challenges, PRX Quantum 5, 037001 (2024).
  115. D. M. Tibaduiza, L. Pires, A. L. C. Rego, D. Szilard, C. Zarro, and C. Farina, A time-dependent harmonic oscillator with two frequency jumps: An exact algebraic solution, Braz. J. Phys. 50, 634 (2020).
  116. D. Martínez-Tibaduiza, A. H. Aragão, C. Farina, and C. A. D. Zarro, New BCH-like relations of the su(1, 1), su(2) and so(2, 1) Lie algebras, Phys. Lett. A 384, 126937 (2020).
  117. D. E. Bruschi, A. Xuereb, and R. Zeier, Deciding finiteness of bosonic dynamics with tunable interactions, J. Phys. A: Math. Theor. 58, 025204 (2025).

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