Quantum simulation of Kibble-Zurek mechanism with a semiconductor electron charge qubit

TL;DR

This paper demonstrates a quantum simulation of the Kibble-Zurek mechanism using a semiconductor electron charge qubit, revealing how topological defects form during non-equilibrium phase transitions.

Contribution

It introduces a novel simulation approach of the Kibble-Zurek mechanism with a semiconductor charge qubit, linking Landau-Zener dynamics to topological defect formation.

Findings

Reproduced Kibble-Zurek dependence of defect density on quench rate

Used a single electron charge qubit to simulate non-equilibrium phase transitions

Showed controllability of semiconductor qubits for studying topological defect formation

Abstract

The Kibble-Zurek mechanism provides a description of the topological structure occurring in the symmetry breaking phase transitions, which may manifest as the cosmological strings in the early universe or vortex lines in the superfulid. A particularly intriguing analogy between Kibble-Zurek mechanism and a text book quantum phenomenon, Landau-Zener transition has been discovered, but is difficult to observe up to now. In recent years, there has been broad interest in quantum simulations using different well-controlled physical setups, in which full tunability allows access to unexplored parameter regimes. Here we demonstrate a proof-of-principle quantum simulation of Kibble-Zurek mechanism using a single electron charge qubit in double quantum dot, set to behave as Landau-Zener dynamics. We measure the qubit states as a function of driven pulse velocity and successfully reproduce Kibble-Zurek like dependence of topological defect density on the quench rate. The high-level controllability of semiconductor two-level system make it a platform to test the key elements of topological defect formation process and shed a new insight on the aspect of non-equilibrium phase transitions.