Subscribe to the gold package and get unlimited access to Shamra Academy
Register a new userGeneration of mechanical interference fringes by multi-photon counting
434
0
0.0
(
0
)
Ask ChatGPT about the research
No Arabic abstract
Exploring the quantum behaviour of macroscopic objects provides an intriguing avenue to study the foundations of physics and to develop a suite of quantum-enhanced technologies. One prominent path of study is provided by quantum optomechanics which utilizes the tools of quantum optics to control the motion of macroscopic mechanical resonators. Despite excellent recent progress, the preparation of mechanical quantum superposition states remains outstanding due to weak coupling and thermal decoherence. Here we present a novel optomechanical scheme that significantly relaxes these requirements allowing the preparation of quantum superposition states of motion of a mechanical resonator by exploiting the nonlinearity of multi-photon quantum measurements. Our method is capable of generating non-classical mechanical states without the need for strong single photon coupling, is resilient against optical loss, and offers more favourable scaling against initial mechanical thermal occupation than existing schemes. Moreover, our approach allows the generation of larger superposition states by projecting the optical field onto NOON states. We experimentally demonstrate this multi-photon-counting technique on a mechanical thermal state in the classical limit and observe interference fringes in the mechanical position distribution that show phase superresolution. This opens a feasible route to explore and exploit quantum phenomena at a macroscopic scale.
rate research
Read More
We observe spatial fringes in the interference of two beams, which are controlled by a third beam through the phenomenon of induced coherence without induced emission. We show that the interference pattern depends on the alignment of this beam in an analogous way as fringes created in a traditional division-of-amplitude interferometer depend on the relative alignment of the two interfering beams. We demonstrate that the pattern is characterized by an equivalent wavelength, which corresponds to a combination of the wavelengths of the involved physical light beams.
The ability to coherently control mechanical systems with optical fields has made great strides over the past decade, and now includes the use of photon counting techniques to detect the non-classical nature of mechanical states. These techniques may soon be used to perform an opto-mechanical Bell test, hence highlighting the potential of cavity opto-mechanics for device-independent quantum information processing. Here, we propose a witness which reveals opto-mechanical entanglement without any constraint on the global detection efficiencies in a setup allowing one to test a Bell inequality. While our witness relies on a well-defined description and correct experimental calibration of the measurements, it does not need a detailed knowledge of the functioning of the opto-mechanical system. A feasibility study including dominant sources of noise and loss shows that it can readily be used to reveal opto-mechanical entanglement in present-day experiments with photonic crystal nanobeam resonators.
We investigate a general scheme for generating, either dynamically or in the steady state, continuous variable entanglement between two mechanical resonators with different frequencies. We employ an optomechanical system in which a single optical cavity mode driven by a suitably chosen two-tone field is coupled to the two resonators. Significantly large mechanical entanglement can be achieved, which is extremely robust with respect to temperature.
Observing a physical quantity without disturbing it is a key capability for the control of individual quantum systems. Such back-action-evading or quantum-non-demolition measurements were first introduced in the 1970s in the context of gravitational wave detection to measure weak forces on test masses by high precision monitoring of their motion. Now, such techniques have become an indispensable tool in quantum science for preparing, manipulating, and detecting quantum states of light, atoms, and other quantum systems. Here we experimentally perform rapid optical quantum-noise-limited measurements of the position of a mechanical oscillator by using pulses of light with a duration much shorter than a period of mechanical motion. Using this back-action evading interaction we performed both state preparation and full state tomography of the mechanical motional state. We have reconstructed mechanical states with a position uncertainty reduced to 19 pm, limited by the quantum fluctuations of the optical pulse, and we have performed `cooling-by-measurement to reduce the mechanical mode temperature from an initial 1100 K to 16 K. Future improvements to this technique may allow for quantum squeezing of mechanical motion, even from room temperature, and reconstruction of non-classical states exhibiting negative regions in their phase-space quasi-probability distribution.
Quantum optical measurement techniques offer a rich avenue for quantum control of mechanical oscillators via cavity optomechanics. In particular, a powerful yet little explored combination utilizes optical measurements to perform heralded non-Gaussian mechanical state preparation and to determine the mechanical phase-space distribution. Here, we experimentally perform heralded single- and multi-phonon subtraction via photon counting to a room temperature mechanical thermal state with a Brillouin optomechanical system, and use optical heterodyne detection to measure the $s$-parameterized Wigner phase-space distribution of the non-Gaussian mechanical states generated. The techniques developed here will be useful for a broad range of both applied and fundamental studies that exploit quantum-state engineering and reconstruction of mechanical motional states.
Log in to be able to interact and post comments
comments
Fetching comments
Sign in to be able to follow your search criteria
