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Related papers: Evading Vacuum Noise: Wigner Projections or Husimi…

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We introduce a family of criteria to detect quantum non-Gaussian states of a harmonic oscillator, that is, quantum states that can not be expressed as a convex mixture of Gaussian states. In particular we prove that, for convex mixtures of…

Randomness is a key feature of quantum physics. Heisenberg's uncertainty principle reveals the existence of an intrinsic noise, usually explored through Gaussian squeezed states. Due to their insufficiency for quantum advantage, the focus…

Quantum Physics · Physics 2025-11-20 Vojtěch Kala , Jiří Fadrný , Michal Neset , Jan Bílek , Petr Marek , Miroslav Ježek

The standard technique for measuring the phase of a single mode field is heterodyne detection. Such a measurement may have an uncertainty far above the intrinsic quantum phase uncertainty of the state. Recently it has been shown [H. M.…

Quantum Physics · Physics 2009-10-31 D. W. Berry , H. M. Wiseman , Zhong-Xi Zhang

We propose a scheme to measure the quantum state of a nanomechanical oscillator cooled near its ground state of vibrational motion. This is an extension of the nonlinear atomic homodyning technique scheme first developed to measure the…

Quantum Physics · Physics 2009-08-12 Swati Singh , Pierre Meystre

Quantum states at optical frequencies are often generated inside cavities to facilitate strong nonlinear interactions. However, measuring these quantum states with traditional homodyne techniques poses a challenge, as outcoupling from the…

We present a comprehensive theory and an easy to follow method for the design and construction of a wideband homodyne detector for time-domain quantum measurements. We show how one can evaluate the performance of a detector in a specific…

Instrumentation and Detectors · Physics 2015-06-03 Ranjeet Kumar , Erick Barrios , Andrew MacRae , E. Cairns , E. H. Huntington , A. I. Lvovsky

Quantum state tomography, aimed at deriving a classical description of an unknown state from measurement data, is a fundamental task in quantum physics. In this work, we analyse the ultimate achievable performance of tomography of…

We suggest and demonstrate a tomographic method to fully characterize homodyne detectors at the quantum level. The operator measure associated with the detector is expanded in the quadrature basis and probed with a set of coherent states.…

Quantum Physics · Physics 2024-02-15 Samuele Grandi , Alessandro Zavatta , Marco Bellini , Matteo G. A. Paris

Elementary particle detectors fall broadly into only two classes: phase-transformation devices, such as the bubble chamber, and charge-transfer devices like the Geiger-Mueller tube. Quantum measurements are seen to involve transitions from…

Quantum Physics · Physics 2015-09-30 R. Merlin

The single photon detectors currently used in quantum communication schemes impose considerable restrictions on signal registration and dark count rates, require cooling to low temperatures, and are relatively expensive. Alternative…

Continuous-variable (CV) photonic states are of increasing interest in quantum information science, bolstered by features such as deterministic resource state generation and error correction via bosonic codes. Data-efficient…

Quantum Physics · Physics 2022-11-22 Joseph C. Chapman , Joseph M. Lukens , Bing Qi , Raphael C. Pooser , Nicholas A. Peters

We find and investigate the optimal scheme of quantum distributed Gaussian sensing for estimation of the average of independent phase shifts. We show that the ultimate sensitivity is achievable by using an entangled symmetric Gaussian…

Quantum Physics · Physics 2020-04-14 Changhun Oh , Changhyoup Lee , Seok Hyung Lie , Hyunseok Jeong

Continuous variable remote state preparation and teleportation are analyzed using Wigner functions in phase space. We suggest a remote squeezed state preparation scheme between two parties sharing an entangled twin beam, where homodyne…

Quantum Physics · Physics 2009-11-07 Matteo G. A. Paris , Mary Cola , Rodolfo Bonifacio

The accuracy of the Arthurs-Kelly model of a simultaneous measurement of position and momentum is analysed using concepts developed by Braginsky and Khalili in the context of measurements of a single quantum observable. A distinction is…

Quantum Physics · Physics 2008-11-26 D. M. Appleby

In quantum mechanics, the process of measurement is a subtle interplay between extraction of information and disturbance of the state of the quantum system. A quantum non-demolition (QND) measurement minimizes this disturbance by using a…

Superconductivity · Physics 2015-06-25 A. Lupascu , S. Saito , T. Picot , P. C. de Groot , C. J. P. M. Harmans , J. E. Mooij

In quantum physics, all measured observables are subject to statistical uncertainties, which arise from the quantum nature as well as the experimental technique. We consider the statistical uncertainty of the so-called sampling method, in…

Quantum Physics · Physics 2012-06-08 Thomas Kiesel

We give a systematic theoretical description of homodyne detection in the case where both the signal and the local oscillator pass through the turbulent atmosphere. Imperfect knowledge of the local-oscillator amplitude is effectively…

Quantum Physics · Physics 2012-06-05 A. A. Semenov , F. Töppel , D. Yu. Vasylyev , H. V. Gomonay , W. Vogel

Quantum feedback control is a technology which can be used to drive a quantum system into a predetermined eigenstate. In this article, sufficient conditions for the experiment parameters of a quantum feedback control process of a homodyne…

Quantum Physics · Physics 2007-05-23 Andreas de Vries

Quantum gas microscopes offer unprecedented insights into quantum many-body states of cold atomic gases. Here we introduce concrete protocols for extending quantum gas microscopes to measure in phase space, by mapping momentum onto…

Quantum Gases · Physics 2026-04-01 N. R. Cooper , Y. Yang , C. Weitenberg

The state space of a homogeneous body is derived under two different assumptions: infinitesimal reducibility and irreducibility. The first assumption leads to a real vector space, used in classical mechanics, while the second one leads to a…

Quantum Physics · Physics 2012-03-19 Gabriele Carcassi