Two-qubit entanglement generation through non-Hermitian Hamiltonians induced by repeated measurements on an ancilla

TL;DR

This paper demonstrates how repeated measurements on an ancilla can induce non-Hermitian Hamiltonian dynamics in a quantum system, leading to maximally entangled stationary states and offering new simulation methods.

Contribution

It introduces a practical protocol for engineering non-Hermitian Hamiltonians via measurements, enabling entanglement generation and simulation of non-Hermitian quantum dynamics.

Findings

Effective non-Hermitian Hamiltonian drives systems to maximally entangled states

Protocol applicable to multi-spin models

Potential for simulating non-Hermitian quantum systems

Abstract

In contrast to classical systems, actual implementation of non-Hermitian Hamiltonian dynamics for quantum systems is a challenge because the processes of energy gain and dissipation are based on the underlying Hermitian system-environment dynamics that is trace preserving. Recently, a scheme for engineering non-Hermitian Hamiltonians as a result of repetitive measurements on an anicillary qubit has been proposed. The induced conditional dynamics of the main system is described by the effective non-Hermitian Hamiltonian arisng from the procedure. In this paper we demonstrate the effectiveness of such a protocol by applying it to physically relevant multi-spin models, showing that the effective non-Hermitian Hamiltonian drives the system to a maximally entangled stationary state. In addition, we report a new recipe to construct a physical scenario where the quantum dynamics of a physical system represented by a given non-Hermitian Hamiltonian model may be simulated. The physical implications and the broad scope potential applications of such a scheme are highlighted.