Stochastic Approach to Non-Equilibrium Quantum Spin Systems

Understand

We investigate a stochastic approach to non-equilibrium quantum spin systems based on recent insights linking quantum and classical dynamics.

• Exploiting a sequence of exact transformations, quantum expectation values can be recast as averages over classical stochastic processes.
• We illustrate this approach for the quantum Ising model by extracting the Loschmidt amplitude and the magnetization dynamics from the numerical solution of stochastic differential equations.
• We show that dynamical quantum phase transitions are accompanied by clear signatures in the associated classical distribution functions, including the presence of enhanced fluctuations.