Engineered Reservoirs for Thermalization of Many-Body Quantum Systems

Engineering genuine thermal states in quantum analog simulation platforms are addressed by a technique based on a many-body spin Hamiltonians coupled to driven, dissipative ancilla spins. A Born-Markov master equation describing the dynamics of a many-body system coupled to fast-relaxing, driven ancilla qubits is developed, and if the ancilla energies are periodically modulated and swept across the system energy spectrum, with a carefully chosen hierarchy of timescales, one can effectively thermalize a many-body system. Analytical proofs and numerical investigations are used to validate the requirements of thermalization and demonstrate the true thermal state is an approximate dynamical fixed point.