Version 0.4.0

This open source project aims to facilitate versatile numerical tools to efficiently compute the dynamics of quantum systems that are possibly strongly coupled to structured environments. It allows to conveniently apply several numerical methods related to the time evolving matrix product operator (TEMPO) [1-2] and the process tensor (PT) approach to open quantum systems [3-5]. This includes methods to compute ...

• the dynamics of a quantum system strongly coupled to a bosonic environment [1-2].
• the process tensor of a quantum system strongly coupled to a bosonic environment [3-4].
• optimal control procedures for non-Markovian open quantum systems [5].
• the dynamics of a strongly coupled bosonic environment [6].
• the dynamics of a quantum system coupled to multiple non-Markovian environments [7].
• the dynamics of a chain of non-Markovian open quantum systems [8].
• the dynamics of an open many-body system with one-to-all light-matter coupling [9].

(in OQuPy 0.4.0 the open many-body system method was extended to accommodate multiple types of system in the same calculation)

Changes since version 0.3.3

Version 0.4.0

• Extension of mean-field evolution code to accommodate multiple types of system in the same calculation
• Quadrature propagator construction for time dependent Hamiltonians (#41)

Major code contributions

Lead development by Gerald E. Fux

Version 0.4.0

• Joel Beckles and Piper Fowler-Wright: Extension of mean-field evolution to multiple types of system

Version 0.3.0

• Piper Fowler-Wright: Open quantum systems with mean-field evolution [9]

Version 0.2.0

• Gerald E. Fux: Chains of open quantum systems [8].
• Dainius Kilda: Precursor code for chains of open quantum systems [8].
• Dominic Gribben: Bath dynamics extension [6].
• Dominic Gribben: Multiple environments extension [7].

Version 0.1.2 (TimeEvolvingMPO)

• Gerald E. Fux: Improved memory cut-off [1].

Version 0.1.1 (TimeEvolvingMPO)

• No major code contributions in this version.

Version 0.1.0 (TimeEvolvingMPO)

• Gerald E. Fux: Implement process tensor TEMPO (API and backend) [3-5].
• Gerald E. Fux: Implement core TEMPO functionality (API and backend) [2].
• Gerald E. Fux: Setup Project (CI, API design, project planning, etc.).

Bibliography

• [1] Strathearn et al., New J. Phys. 19(9), p.093009 (2017).
• [2] Strathearn et al., Nat. Commun. 9, 3322 (2018).
• [3] Pollock et al., Phys. Rev. A 97, 012127 (2018).
• [4] Jørgensen and Pollock, Phys. Rev. Lett. 123, 240602 (2019).
• [5] Fux et al., Phys. Rev. Lett. 126, 200401 (2021).
• [6] Gribben et al., arXiv:20106.0412 (2021).
• [7] Gribben et al., PRX Quantum 3, 10321 (2022).
• [8] Fux et al., arXiv:2201.05529 (2022).
• [9] Fowler-Wright at al., Phys. Rev. Lett. 129, 173001 (2022).