# Environments of Open Quantum Systems

written by Paul Menczel and Gerardo Suarez

QuTiP can describe environments of open quantum systems. They can be passed to various solvers, where their influence is taken into account exactly or approximately. In the following, we will discuss bosonic and fermionic thermal environments. In our definitions, we follow [BoFiN23].

Note that currently, we only support a single coupling term per environment. If a more generalized coupling would be useful to you, please let us know on GitHub.

- Bosonic Environments
  - Theory
  - Pre-defined Environments
  - User-Defined Environments
  - Multi-Exponential Approximations
- Fermionic Environments
  - Theory
  - Lorentzian Environment
  - Multi-Exponential Fermionic Environment
- Approximations
  - Approximating Bosonic Environments
  - Fitting Methods
  - API Documentation