Single-Phonon Addition and Subtraction to a Mechanical Thermal State

Abstract

Adding or subtracting a single quantum of excitation to a thermal state of a bosonic system has the counter-intuitive effect of approximately doubling its mean occupation. We perform the first experimental demonstration of this effect outside optics by implementing single-phonon addition and subtraction to a thermal state of a mechanical oscillator via Brillouin optomechanics in an optical whispering-gallery microresonator. Using a detection scheme that combines single-photon counting and optical heterodyne detection, we observe this doubling of the mechanical thermal fluctuations to a high precision. The capabilities of this joint click-dyne detection scheme adds a significant new dimension for optomechanical quantum science and applications.

Non-Gaussian mechanical motion via single and multi-phonon subtraction from a thermal state

“…We observe that the initial thermal state is transformed by these operations from an initial Gaussian in phase space into a ring shape with a diameter that increases with the number of phonons subtracted. Building on established results in quantum optics and recent work demonstrating that the mechanical mean thermal occupation doubles for single-phonon addition and subtraction [35], here we also observe that the mean thermal occupation triples for twophonon subtraction. This work expands the toolkit for optical control and readout of mechanical states, and can be applied to future room-temperature or cryogenic experiments to exploit and characterize the non-Gaussian and non-classical properties these operations generate.…”

“…Within optomechanics there have been several recent developments in this direction, with many experimental approaches being utilized to take advantage of the parameters and capabilities provided by fully engineered optomechanical devices. For instance, experiments exploiting quantum measurements with single-photon detectors include generating non-classical states of high-frequency vibrations in diamond crystals [29][30][31] and photonic-crystal structures [32], second-order-coherence measurements of mechanical modes [33,34], the generation of mechanical interference fringes [40], and single-phonon addition or subtraction to a thermal state that results in a doubling of the mean thermal occupation [35]. There is also significant progress towards developing the experimental tools needed for mechanical phase-space tomography or reconstruction [36][37][38][39][40]; however, all of these experiments have insufficient sensitivity to resolve features below the mechanical zero-point motion, and phase-space tomography or reconstruction [41] of a mechanical quantum state remains as an outstanding goal in optomechanics.…”

Nonclassical photon statistics in two-tone continuously driven optomechanics

“…This requires that the system is in the resolved sideband regime ω m > κ. We note that several of the experimental setups where single sideband photon detection have been implemented are indeed in this regime [11][12][13][14].…”

“…This technique requires frequency filtering of the cavity output in order to remove the large amount of photons at the carrier frequency. This has been achieved with mechanical modes of microresonators having resonance frequencies in the GHz regime [11][12][13], with an acoustic mode of helium with frequency around 300 MHz [14], and lately, even with flexural dielectric membrane modes in the MHz regime [15].…”

Measuring High-Order Phonon Correlations in an Optomechanical Resonator

“…The optical equivalents of such states have been shown to be efficient at performing work and carrying information [33]. The ability to create and probe these states in an acoustic mode, as demonstrated here, extends the potential use of such states to optomechanical platforms [34][35][36].…”