Collisional-model quantum trajectories for entangled qubit environments

TL;DR

This paper develops a framework for understanding the dynamics of quantum systems interacting with entangled qubit streams, revealing new features in quantum trajectories depending on measurement basis.

Contribution

It introduces a detailed framework for conditional quantum trajectories in entangled qubit environments, including jump and diffusive types, with novel features not seen in traditional models.

Findings

Quantum trajectories can be jump-type or diffusive depending on measurement basis.

Trajectories exhibit unique features not present in optical or single-qubit cases.

Remote atom entanglement dynamics can be heralded by jump events.

Abstract

We study the dynamics of quantum systems interacting with a stream of entangled qubits. Under fairly general conditions, we present a detailed framework describing the conditional dynamical maps for the system, called quantum trajectories, when the qubits are measured. Depending on the measurement basis, these quantum trajectories can be jump-type or diffusive-type, and they can exhibit features not present with quantum optical and single-qubit trajectories. As an example, we consider the case of two remote atoms, where jump-type quantum trajectories herald the birth and death of entanglement.