Quantum-enhanced accelerometry with a non-linear electromechanical circuit

TL;DR

This paper proposes a quantum-enhanced accelerometry scheme using a non-linear electromechanical circuit with Kerr oscillators, enabling improved force sensitivity through quantum state processing and measurement.

Contribution

It introduces a novel quantum circuit design utilizing Kerr oscillators for creating and processing quantum states to enhance force measurement sensitivity.

Findings

Analytic expressions for circuit performance including noise and loss

Demonstration of quantum state creation and processing with Kerr oscillators

Discussion of experimental feasibility with current technology

Abstract

It is known that placing a mechanical oscillator in a superposition of coherent states allows, in theory, a measurement of a linear force whose sensitivity increases with the amplitude of the mechanical oscillations, a uniquely quantum effect. Further, entangled versions of these states across a network of $n$ mechanical oscillators enables a measurement whose sensitivity increases linearly with $n$, thus improving over the classical scaling by $\sqrt{n}$. One of the key challenges in exploiting this effect is processing the signal so that it can be readily measured; linear processing is insufficient. Here we show that a Kerr oscillator will not only create the necessary states, but also perform the required processing, transforming the quantum phase imprinted by the force signal into a shift in amplitude measurable with homodyne detection. This allows us to design a relatively simple quantum electro-mechanical circuit that can demonstrate the core quantum effect at the heart of this scheme, amplitude-dependent force sensitivity. We derive analytic expressions for the performance of the circuit, including thermal mechanical noise and photon loss. We discuss the experimental challenges in implementing the scheme with near-term technology.