Southwest Quantum Information and Technology

Quantum digital simulator interacting with a bath

Presenting Author: Yi-Cong Zheng, Centre for Quantum Technologies, Yale-NUS college
Contributing Author(s): Hui-Khoon Ng

For a quantum digital simulator simulating a closed many-body quantum system, we ask the following questions: if both systems interacting with the same bath in the same way, will the dynamics of the target system and simulator behave somewhat close to each other? In this paper, we study the open system dynamics of both target system and their digital simulator by solving their time-convolutionless non-Markovian master equations and comparing their density matrices every simulation cycle. We give conditions when their stroboscopic behavior are close to each other analytically: that is, the gate period needs to be much smaller than both bath correlation time and the simulation cycle; meanwhile, the simulation cycle needs to be either much longer or much shorter than the bath correlation time. Numerical simulation of the open system dynamics for a simplified Kitaev toric code model in a thermal boson bath is carried out to verify the validity of these conditions, surprisingly, the fast speed of gate sequence alone is not enough to keep the nature of decoherence process. This result may shed light on developing new methods of quantum error correction and Gibbs state preparation.¹

(Session 5 : Thursday from 5:00pm - 7:00pm)