Quantum Simulation with Non-Unitary Dynamics

Many-body quantum simulation using experimental quantum processors is a highly promising avenue toward practical quantum advantage. Traditionally, such a task is accomplished via unitary dynamics which is limited by gate fidelities and oftentimes Trotter errors. Here we explore the non-unitary dynamics arising from the interplay between unitary evolution applied to a system of qubits and an engineered dissipative environment realized by auxiliary qubits that are frequently reset to their ground states. We find that by appropriate choice of interaction between the system qubits and auxiliaries, the quantum system may be steered to an entangled steady state resembling low-temperature states of 1D and 2D transverse Ising models. Furthermore, by coupling the system to auxiliaries stabilized to different states, we discover a new, subdiffusive form of quantum transport in the Heisenberg XXZ model. These results demonstrate the feasibility of utilizing engineered dissipation toward preparing complex quantum matter, enriching the capability of near-term superconducting processors.