Berlin 2024 – scientific programme

Parts | Days | Selection | Search | Updates | Downloads | Help

QI: Fachverband Quanteninformation

QI 22: Quantum Simulation I

QI 22.7: Talk

Thursday, March 21, 2024, 11:30–11:45, HFT-FT 101

Prolonging a discrete time crystal by quantum-classical feedback — •Gonzalo Camacho¹ and Benedikt Fauseweh^1,2 — ¹German Aerospace Center (DLR), Institute für Softwaretechnologie, Rathausalle 12, 53757, Sankt Augustin, Germany — ²TU Dortmund, Department of Physics, Otto-Hahn-Str 4, 44227 Dortmund, Germany

The realization of quantum time crystals on noisy intermediate-scale quantum (NISQ) devices has verified further the potential of employing quantum computers to study non-equilibrium phases of quantum matter. While ideal quantum time crystals exhibit collective sub-harmonic oscillations and spatio-temporal long-range order persisting for infinite times, the decoherence time of current NISQ devices sets a natural limit to the survival of these phases, restricting their observation to a shallow quantum circuit. In this work, we propose a time-periodic scheme that leverages quantum-classical feedback protocols in sub-regions of the system to enhance a time crystal signal significantly exceeding the decoherence time of the device. As a case of study, we focus on the survival of the many-body localized discrete time crystal phase (MBL-DTC) in the one dimensional periodically kicked Ising model, accounting for decoherence of the system with an environment. Based on classical simulation of quantum circuit realizations using tensor networks, we find that this approach is suitable for implementation on existing quantum hardware and presents a prospective path to simulate complex quantum many-body dynamics that transcend the low depth limit of current digital quantum computers.

Keywords: Discrete Time Crystals; Digital Quantum Simulation; Quantum Classical Feedback; Open Quantum Systems; Tensor Networks