Hybrid Mechanical Systems

Abstract

We discuss hybrid systems in which a mechanical oscillator is coupled to another (microscopic) quantum system, such as trapped atoms or ions, solid-state spin qubits, or superconducting devices. We summarize and compare different coupling schemes and describe first experimental implementations. Hybrid systems enable new approaches to quantum control of mechanical objects, precision sensing, and quantum information processing

Displacemon Electromechanics: How to Detect Quantum Interference in a Nanomechanical Resonator

“…In general, strongly coupling a mechanical resonator to a qubit is challenging because the best qubits are engineered to be insensitive to their environment [36]. We propose a design that is robust against electrical and magnetic noise while still achieving strong mechanical coupling.…”

“…The dependence of ω q on X gives rise to an electromechanical coupling, resulting in the Hamiltonian [23,36] …”

Quantum Sensing of Noisy and Complex Systems under Dynamical Control

“…We, however, focus here on the much more robust and readily obtainable classical information on the system by simple quantum probes: either single or correlated qubits that are engineered to possess advantageous properties for the sensing process in question: Thus, superconducting qubits are excellent detectors of microwave or far-infrared photons [2]; Rydberg-atom qubits are highly sensitive probes of dipolar forces; and nitrogen-vacancy centers (NVC) in diamond are the most sensitive magnetometers or electrometers to date [3][4][5][6][7]. We shall not be concerned with the probing of mechanical degrees of freedom (phonon modes) for which the most appropriate probes are harmonic oscillators, as in optomechanical setups [8]. The peculiarity of the approach we present here is that rather than try to maximize the signal-to-noise ratio (SNR) obtainable by the probe, we set out to analyze and extract information from the noise exerted by the system on the probe [9].…”

Optical driving of macroscopic mechanical motion by a single two-level system

“…First experiments were based on the interaction between the electromagnetic field stored in a cavity and a moving mirror, in the so-called linearized regime where the state of both resonators can be described classically [1][2][3]. Recently, it has become possible to realize a similar setup, with a genuinely quantum system [4] in place of the cavity, like a single spin in a diamond Nitrogen Vacancy (NV) center [5], a superconducting qubit [6,7], or a semiconductor quantum dot [8]. In the case of a optically active quantum system, the influence of the mechanical motion on the fluorescence properties has been recently evidenced [9].…”