MQSens

Quantum sensing with nonclassical mechanical oscillators

Recent breakthroughs have led to creating true quantum states of solid-state mechanical objects. Using cavity optomechanics, quantum acoustics, and nano-electro-mechanics, we will develop new protocols for sensing that make use of the unique properties of these states. While quantum limits to noise and sensitivity have long been an important consideration in optomechanical sensors, we aim to make use of distinctly quantum properties such as non-Gaussianity, multi-mode entanglement, and single-phonon nonlinearities to enhance the performance of these systems. In other words, analogously to what has long been done in atomic or spin-based sensors, we will explore using quantum states as a new resource for enhancing the capabilities of mechanical sensors.

The goal of this project is to establish the usefulness of quantum states for mechanical sensing through new theoretical developments and experimental demonstrations in three complimentary physical platforms: high-overtone bulk acoustic wave resonators (HBARs), membrane resonators, and carbon nanotubes. We will begin by addressing three outstanding goals in the field: creating complex non-classical states of motion such as Schrödinger cat states, using feedback to stabilize squeezed and entangled mechanical states, and realizing a mechanical qubit. Achieving these goals will require us to advance the performance of all three mechanical systems and develop new theoretical ideas for dissipation engineering and quantum control. We will then use these capabilities to explore new protocols for quantum-enhanced measurements of force and frequency. Importantly, we will broadly consider these devices as open quantum systems that “sense” their environment and establish technical and conceptual connections to other fields such as quantum error correction and the study of quantum mechanical effects in macroscopic objects.

Our experimental platforms include: (a) High-overtone (HBAR) resonators coupled to transmon qubits. (b) Membrane resonators realized as aluminum drumheads or large silicon nitride membranes. (c) Mechanical qubits formed in a suspended carbon nanotube system.

CONSORTIUM