Linear quantum control of mechanical motion

2015 ◽  
pp. 170-211
Keyword(s):  
Quantum Control ◽  
Mechanical Motion ◽  
Linear Quantum

scholarly journals Real-time optimal quantum control of mechanical motion at room temperature

Nature ◽  
2021 ◽  
Vol 595 (7867) ◽  
pp. 373-377
Author(s):  
Lorenzo Magrini ◽  
Philipp Rosenzweig ◽  
Constanze Bach ◽  
Andreas Deutschmann-Olek ◽  
Sebastian G. Hofer ◽  
...  
Keyword(s):  
Real Time ◽  
Room Temperature ◽  
Quantum Control ◽  
Mechanical Motion ◽  
Time Optimal

scholarly journals Measurement-based quantum control of mechanical motion

Nature ◽  
2018 ◽  
Vol 563 (7729) ◽  
pp. 53-58 ◽  
Author(s):  
Massimiliano Rossi ◽  
David Mason ◽  
Junxin Chen ◽  
Yeghishe Tsaturyan ◽  
Albert Schliesser
Keyword(s):  
Quantum Control ◽  
Mechanical Motion

scholarly journals Quantum control of a nanoparticle optically levitated in cryogenic free-space

2021 ◽  
Author(s):  
Lukas Novotny ◽  
Felix Tebbenjohanns ◽  
Maria Luisa Mattana ◽  
Massimiliano Rossi ◽  
Martin Frimmer
Keyword(s):  
Quantum Mechanics ◽  
Free Space ◽  
Quantum Control ◽  
Center Of Mass ◽  
Trapping Potential ◽  
Matter Wave ◽  
Mass Motion ◽  
Mechanical Motion ◽  
Quantum Ground States ◽  
Detection Schemes

Abstract Tests of quantum mechanics on a macroscopic scale require extreme control over mechanical motion and its decoherence [1-4]. Quantum control of mechanical motion has been achieved by engineering the radiation pressure coupling between a micromechanical oscillator and the electromagnetic field in a resonator [5-8]. Furthermore, measurement-based feedback control relying on cavity-enhanced detection schemes has been used to cool micromechanical oscillators to their quantum ground states [9]. In contrast to mechanically tethered systems, optically levitated nanoparticles are particularly promising candidates for matter-wave experiments with massive objects [10,11], since their trapping potential is fully controllable. In this work, we optically levitate a femto-gram dielectric particle in cryogenic free space, which suppresses thermal effects sufficiently to make the measurement backaction the dominant decoherence mechanism. With an efficient quantum measurement, we exert quantum control over the dynamics of the particle. We cool its center-of-mass motion by measurement-based feedback to an average occupancy of 0.65 motional quanta, corresponding to a state purity of 43%. The absence of an optical resonator and its bandwidth limitations holds promise to transfer the full quantum control available for electromagnetic fields to a mechanical system. Together with the fact that the optical trapping potential is highly controllable, our experimental platform offers a route to investigating quantum mechanics at macroscopic scales [12,13].

scholarly journals Microwave oscillator and frequency comb in a silicon optomechanical cavity with a full phononic bandgap

Nanophotonics ◽  
2020 ◽  
Vol 9 (11) ◽  
pp. 3535-3544 ◽  
Author(s):  
Laura Mercadé ◽  
Leopoldo L. Martín ◽  
Amadeu Griol ◽  
Daniel Navarro-Urrios ◽  
Alejandro Martínez
Keyword(s):  
Phase Noise ◽  
Frequency Comb ◽  
Microwave Oscillator ◽  
New Paradigm ◽  
Mechanical Motion ◽  
Optical Fields ◽  
Optical Resonance ◽  
Processing Elements ◽  
Low Weight ◽  
Harmonic Mixing

AbstractCavity optomechanics has recently emerged as a new paradigm enabling the manipulation of mechanical motion via optical fields tightly confined in deformable cavities. When driving an optomechanical (OM) crystal cavity with a laser blue-detuned with respect to the optical resonance, the mechanical motion is amplified, ultimately resulting in phonon lasing at MHz and even GHz frequencies. In this work, we show that a silicon OM crystal cavity performs as an OM microwave oscillator when pumped above the threshold for self-sustained OM oscillations. To this end, we use an OM cavity designed to have a breathing-like mechanical mode at 3.897 GHz in a full phononic bandgap. Our measurements show that the first harmonic of the detected signal displays a phase noise of ≈−100 dBc/Hz at 100 kHz. Stronger blue-detuned driving leads eventually to the formation of an OM frequency comb, whose lines are spaced by the mechanical frequency. We also measure the phase noise for higher-order harmonics and show that, unlike in Brillouin oscillators, the noise is increased as corresponding to classical harmonic mixing. Finally, we present real-time measurements of the comb waveform and show that it can be fitted to a theoretical model recently presented. Our results suggest that silicon OM cavities could be relevant processing elements in microwave photonics and optical RF processing, in particular in disciplines requiring low weight, compactness and fiber interconnection.

INTEGRABILITY, ENTROPY AND QUANTUM COMPUTATION

1999 ◽  
Vol 10 (07) ◽  
pp. 1205-1228 ◽  
Author(s):  
E. V. KRISHNAMURTHY
Keyword(s):  
Quantum Computation ◽  
Quantum Chaos ◽  
Quantum Control ◽  
Dynamical Evolution ◽  
Open Problems ◽  
Quantum Integrability ◽  
Feynman Path Integrals ◽  
Exact Integrability ◽  
Time Arrow ◽  
Computational Systems

The important requirements are stated for the success of quantum computation. These requirements involve coherent preserving Hamiltonians as well as exact integrability of the corresponding Feynman path integrals. Also we explain the role of metric entropy in dynamical evolutionary system and outline some of the open problems in the design of quantum computational systems. Finally, we observe that unless we understand quantum nondemolition measurements, quantum integrability, quantum chaos and the direction of time arrow, the quantum control and computational paradigms will remain elusive and the design of systems based on quantum dynamical evolution may not be feasible.

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