Programmable simulation of high-order exceptional point with a trapped ion

TL;DR

This paper demonstrates programmable control in a trapped ion system to simulate high-order exceptional points, enabling scalable quantum simulation of complex non-Hermitian systems with potential applications in quantum sensing.

Contribution

It introduces a method for simulating high-order non-Hermitian Hamiltonians in a multi-dimensional trapped ion system, advancing control over complex dissipative quantum phenomena.

Findings

Successfully simulated a fourth-order exceptional point.

Observed coalescence of second-order EPs into higher-order EPs.

Showcased scalable quantum simulation of high-dimensional dissipative systems.

Abstract

The nontrivial degeneracies in non-Hermitian systems, exceptional points (EPs), have attracted extensive attention due to intriguing phenomena. Compared with commonly observed second-order EPs, high-order EPs show rich physics due to their extended dimension and parameter space, ranging from the coalescence of EPs into higher order to potential applications in topological properties. However, these features also pose challenges in controlling multiple coherent and dissipative elements in a scaled system. Here we experimentally demonstrate a native programmable control to simulate a high-order non-Hermitian Hamiltonian in a multi-dimensional trapped ion system. We simulate a series of non-Hermitian systems with varied parameters and observe the coalescence of second-order EPs into a fourth-order EP. Our results pave the way for scalable quantum simulation of high-dimensional dissipative systems and can be beneficial for the application of high-order EPs in quantum sensing and quantum control.