Modeling Quantum Enhanced Sensing on a Quantum Computer

TL;DR

This paper models quantum enhanced sensing using quantum circuits on IBM processors, demonstrating how entanglement improves measurement sensitivity beyond classical limits, inspired by LIGO's advancements.

Contribution

It introduces two quantum circuit models that simulate quantum sensing and entanglement effects on real quantum hardware, illustrating their role in precision measurement.

Findings

Single-qubit interferometer achieves 11% above standard quantum limit.

Two-qubit entangled interferometer achieves 17% below standard quantum limit.

Experiments are accessible and suitable for educational purposes.

Abstract

Quantum computers allow for direct simulation of the quantum interference and entanglement used in modern interferometry experiments with applications ranging from biological sensing to gravitational wave detection. Inspired by recent developments in quantum sensing at the Laser Interferometer Gravitational-wave Observatory (LIGO), here we present two quantum circuit models that demonstrate the role of quantum mechanics and entanglement in modern precision sensors. We implemented these quantum circuits on IBM quantum processors, using a single qubit to represent independent photons traveling through the LIGO interferometer and two entangled qubits to illustrate the improved sensitivity that LIGO has achieved by using non-classical states of light. The one-qubit interferometer illustrates how projection noise in the measurement of independent photons corresponds to phase sensitivity at the standard quantum limit. In the presence of technical noise on a real quantum computer, this interferometer achieves the sensitivity of 11\% above the standard quantum limit. The two-qubit interferometer demonstrates how entanglement circumvents the limits imposed by the quantum shot noise, achieving the phase sensitivity 17\% below the standard quantum limit. These experiments illustrate the role that quantum mechanics plays in setting new records for precision measurements on platforms like LIGO. The experiments are broadly accessible, remotely executable activities that are well suited for introducing undergraduate students to quantum computation, error propagation, and quantum sensing on real quantum hardware.