Quantum amplification of mechanical oscillator motion

Abstract

Detection of the weakest forces in nature is aided by increasingly sensitive measurements of the motion of mechanical oscillators. However, the attainable knowledge of an oscillator’s motion is limited by quantum fluctuations that exist even if the oscillator is in its lowest possible energy state. We demonstrate a technique for amplifying coherent displacements of a mechanical oscillator with initial magnitudes well below these zero-point fluctuations. When applying two orthogonal squeezing interactions, one before and one after a small displacement, the displacement is amplified, ideally with no added quantum noise. We implemented this protocol with a trapped-ion mechanical oscillator and determined an increase by a factor of up to 7.3 (±0.3) in sensitivity to small displacements.

Ramsey interferometry with generalized one-axis twisting echoes

“…Recently, experiments in which simple but wellcontrolled interactions were used several times, in the form of an 'echo', achieved excellent results in a variety of precision measurements [11][12][13][14]. The one-axis-twisting (OAT) interaction for effective two-level systems [15] allows a uniform description of many setups.…”

Weak-force sensing with squeezed optomechanics

“…Our work provides new insight in strengthening the sensitivity of a force sensor with the assistance of intracavity squeezing, which can be also extended into other systems of quantum sensing with e.g., waveguide [84,87], interferometer [88], or parity-time (PT ) symmetric microcavity [89][90][91]. In the future, we plan to extend our work to study the weakforce measurement with the help of two-mode squeezing or quantum entanglement [92][93][94], squeezed mechanical modes [70,95], or squeezed sources in hybrid COM devices [96,97]. In our system, the cavity with resonant frequency ω a and damping rate κ, is driven by an input beam a in at frequency ω l .…”

Heat capacities of thermally manipulated mechanical oscillator at strong coupling

“…To test the quantum non-equilibrium version of this effect, mechanical state of trapped ion with uncertainty squeezed below the ground state can be used. 63 Alternatively, a transient time-dependent squeezing of light can be considered. 64 Such simulator will allow not only to verify our current results, but also to simulate further topics of stochastic and quantum thermodynamics, such as the performance of quantum heat engines at strong coupling, [65][66][67][68][69] including impact of fluctuations on their efficiencies, 70 and the effects of thermally induced coherence.…”