Short-time-interaction quantum measurement through an incoherent mediator

TL;DR

This paper introduces a theory for rapid, indirect quantum measurements using an incoherent mediator, enabling robust quantum state transfer without direct interaction, demonstrated with a qubit-oscillator-qubit system.

Contribution

It presents a novel measurement scheme allowing short-time quantum state readout via an incoherent mediator, expanding possibilities for quantum information transfer.

Findings

Fast quantum information transfer is achievable with robustness.

The scheme works with incoherent interactions and no direct system-probe contact.

Different physical scenarios reveal advantages and limitations.

Abstract

We develop a theory of indirect measurements where a probe is able to read, in short interaction times, the quantum state of a remote system through an incoherent wall. The probe and the system can interact with an ancilla in an incoherent state but not directly among themselves and, nevertheless, the fast transfer of quantum information can be achieved with robustness. We exemplify our measurement scheme with a paradigmatic example of this tripartite problem: qubit-oscillator-qubit, and discuss different physical scenarios pointing out the associated advantages and limitations.