Conference on Lasers and Electro-Optics Europe & European Quantum Electronics Conference (CLEO/Europe-EQEC)

Generation of mechanical interference fringes by multi-photon quantum measurement

Martin Ringbauer, Till J. Weinhold, Andrew G. White, Michael Ross Vanner

Published Jun 1, 2017• 1 citation

Abstract

Summary form only given. One of the cornerstones of quantum mechanics is that matter can possess both particle- and wave-like properties. Since the inception of quantum mechanics, such wavelike behaviour has been observed in ever more massive systems - ranging from electrons, neutrons, ultracold atoms, and even large molecules comprising many hundreds of atoms. An exciting route to further extend the exploration of quantum phenomena to a macroscopic regime is through the study of quantum optomechanics, where optical fields are used to manipulate the motion of mechanical resonators using radiation pressure. We introduce a method for preparing non-classical states of motion for an optomechanical system which, using the non-linearity of single-photon measurements, is independent of the initial thermal occupation of the resonator and does not require strong single-photon coupling. We demonstrate this method in a thermal regime and observe interference fringes in the position quadrature distribution of a SiN membrane [1].

DOI: 10.1109/cleoe-eqec.2017.8087385

Related papers

Generation of mechanical interference fringes by multi-photon counting

Martin Ringbauer, Till J. Weinhold, L. A. Howard +2 more

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 super-resolution. This opens a feasible route to explore and exploit quantum phenomena at a macroscopic scale.

arXiv:1602.05955New Journal of PhysicsMay 18, 201831 citations

Growing macroscopic superposition states via cavity quantum optomechanics

Jack Clarke, Michael Ross Vanner

The investigation of macroscopic quantum phenomena is a current active area of research that offers significant promise to advance the forefronts of both fundamental and applied quantum science. Utilising the exquisite precision and control of quantum optics provides a powerful toolset for generating such quantum states where the types and 'size' of the states that can be generated are set by the experimental parameter regime available and the resourcefulness of the protocol applied. In this work we present a new multistep scheme to 'grow' macroscopic superposition states of motion of a mechanical oscillator via cavity quantum optomechanics. The scheme consists of a series of optical pulses interacting with a mechanical mode via radiation-pressure followed by photon-counting measurements. The multistep nature of our protocol allows macroscopic superposition states to be prepared with a relaxed requirement for the single-photon optomechanical coupling strength. To illustrate the experimental feasibility of our proposal, we quantify how initial mechanical thermal occupation and mechanical decoherence affects the non-classicality and macroscopicity of the states generated and show that our scheme is resilient to optical loss. The advantages of this protocol provide a promising path to grow non-classical mechanical quantum states to a macroscopic scale under realistic experimental conditions.

arXiv:1805.09334Quantum Science and TechnologyAug 14, 201831 citations

Nonlinear optomechanical measurement of mechanical motion

George A. Brawley, Michael Ross Vanner, Peter Emil Larsen +3 more

Precision measurement of nonlinear observables is an important goal in all facets of quantum optics. This allows measurement-based non-classical state preparation, which has been applied to great success in various physical systems, and provides a route for quantum information processing with otherwise linear interactions. In cavity optomechanics much progress has been made using linear interactions and measurement, but observation of nonlinear mechanical degrees-of-freedom remains outstanding. Here we report the observation of displacement-squared thermal motion of a micro-mechanical resonator by exploiting the intrinsic nonlinearity of the radiation-pressure interaction. Using this measurement we generate bimodal mechanical states of motion with separations and feature sizes well below 100 pm. Future improvements to this approach will allow the preparation of quantum superposition states, which can be used to experimentally explore collapse models of the wavefunction and the potential for mechanical-resonator-based quantum information and metrology applications.

arXiv:1404.5746Nature CommunicationsMar 21, 2016146 citations

Limitations of a measurement-assisted optomechanical route to quantum macroscopicity of superposition states

Andrew Carlisle, Hyukjoon Kwon, Hyunseok Jeong +2 more

Optomechanics is currently believed to provide a promising route towards the achievement of genuine quantum effects at the large, massive-system scale. By using a recently proposed figure of merit that is well suited to address continuous-variable systems, in this paper we analyze the requirements needed for the state of a mechanical mode (embodied by an end-cavity cantilever or a membrane placed within an optical cavity) to be qualified as macroscopic. We show that according to the phase-space-based criterion that we have chosen for our quantitative analysis, the state achieved through strong single-photon radiation-pressure coupling to a quantized field of light and conditioned by measurements operated on the latter might be interpreted as macroscopically quantum. In general, though, genuine macroscopic quantum superpositions appear to be possible only under quite demanding experimental conditions.

arXiv:1411.7980Physical Review AAug 26, 20157 citations

Quantumness in optomechanics

Ludovico Latmiral

Cavity optomechanics has become an established and equally promising branch in quantum optics. Thanks to the interaction between matter and electromagnetic radiation, it has proved to be an optimal platform for a range of scopes, from weak force sensing to the study of non-classicality of mechanical motion. Besides, the capability to isolate genuine quantum features of the interaction represents a test ground to address many important questions regarding decoherence, quantum-to-classical transitions and the interface between quantum mechanics and gravity. The first part of the research embedded in this thesis is addressed towards the clear identification and characterisation of quantum features in optomechanics. The main model we will refer to is a deformable Fabry-P\'erot cavity where one of the two mirrors moves under the radiation pressure of light. After having properly assessed the quantum peculiarities of the system, and also having revised some intakes from past literature, we will focus on the study of mechanical non-linearities, as they have been proved to be a key resource to bring out and enhance quantum properties. These investigations provide the basis to eventually propose a method to deterministically prepare and measure macroscopic quantum superposition states of the movable mirror. Such massive quantum states play a key role to inspect the foundations of physics, e.g. to test the collapse of the wave function and phenomenological models of quantum gravity, as well as to develop new enhanced quantum technologies.

Jul 1, 20170 citations

Optomechanical state reconstruction and nonclassicality verification beyond the resolved-sideband regime

Farid Shähandeh, Martin Ringbauer

Quantum optomechanics uses optical means to generate and manipulate quantum states of motion of mechanical resonators. This provides an intriguing platform for the study of fundamental physics and the development of novel quantum devices. Yet, the challenge of reconstructing and verifying the quantum state of mechanical systems has remained a major roadblock in the field. Here, we present a novel approach that allows for tomographic reconstruction of the quantum state of a mechanical system without the need for extremely high quality optical cavities. We show that, without relying on the usual state transfer presumption between light an mechanics, the full optomechanical Hamiltonian can be exploited to imprint mechanical tomograms on a strong optical coherent pulse, which can then be read out using well-established techniques. Furthermore, with only a small number of measurements, our method can be used to witness nonclassical features of mechanical systems without requiring full tomography. By relaxing the experimental requirements, our technique thus opens a feasible route towards verifying the quantum state of mechanical resonators and their nonclassical behaviour in a wide range of optomechanical systems.

arXiv:1709.01135QuantumFeb 25, 20193 citations