scholarly journals Quantum Measurements in Atom Optics

1996 ◽  
Vol 49 (4) ◽  
pp. 715 ◽  
Author(s):  
DF Walls
Keyword(s):  
Degrees Of Freedom ◽  
Recent Progress ◽  
Light Field ◽  
Photon Number ◽  
Quantum Measurements ◽  
Quantum States ◽  
Atom Optics ◽  
Atomic Position ◽  
External Degrees

We review recent progress in atom optics. We describe new quantum measurements based on the entanglement of quantum states of a light field with atomic external degrees of freedom. Examples include the quantum non-demolition measurement of the photon number in a cavity and the measurement of atomic position.

Entanglement between internal and external degrees of freedom of a driven trapped atom

2010 ◽  
Vol T140 ◽  
pp. 014034 ◽  
Author(s):  
Maryam Roghani ◽  
Hanspeter Helm ◽  
Heinz-Peter Breuer
Keyword(s):  
Degrees Of Freedom ◽  
External Degrees

scholarly journals Entanglement in massive coupled oscillators

2011 ◽  
Vol 11 (3&4) ◽  
pp. 278-299
Author(s):  
Nathan L. Harshman ◽  
William F. Flynn
Keyword(s):  
Coupled Oscillators ◽  
Coherent States ◽  
Degrees Of Freedom ◽  
Classical Model ◽  
Reduced Density Matrix ◽  
One Dimension ◽  
Atomic Position ◽  
Pure States ◽  
Non Gaussian ◽  
Reduced Density

This article investigates entanglement of the motional states of massive coupled oscillators. The specific realization of an idealized diatomic molecule in one-dimension is considered, but the techniques developed apply to any massive particles with two degrees of freedom and a quadratic Hamiltonian. We present two methods, one analytic and one approximate, to calculate the interatomic entanglement for Gaussian and non-Gaussian pure states as measured by the purity of the reduced density matrix. The cases of free and trapped molecules and hetero- and homonuclear molecules are treated. In general, when the trap frequency and the molecular frequency are very different, and when the atomic masses are equal, the atoms are highly-entangled for molecular coherent states and number states. Surprisingly, while the interatomic entanglement can be quite large even for molecular coherent states, the covariance of atomic position and momentum observables can be entirely explained by a classical model with appropriately chosen statistical uncertainty.

Homodyne-like detection scheme based on photon-number-resolving detectors

2017 ◽  
Vol 15 (08) ◽  
pp. 1740016 ◽  
Author(s):  
Alessia Allevi ◽  
Matteo Bina ◽  
Stefano Olivares ◽  
Maria Bondani
Keyword(s):  
Coherent States ◽  
Beam Splitter ◽  
Photon Number ◽  
Local Oscillator ◽  
Quantum States ◽  
Homodyne Detection ◽  
Detection Scheme ◽  
Light Signals ◽  
The Difference ◽  
Signal Field

Homodyne detection is the most effective detection scheme employed in quantum optics to characterize quantum states. It is based on mixing at a beam splitter the signal to be measured with a coherent state, called the “local oscillator,” and on evaluating the difference of the photocurrents of two photodiodes measuring the outputs of the beam splitter. If the local oscillator is much more intense than the field to be measured, the homodyne signal is proportional to the signal-field quadratures. If the local oscillator is less intense, the photodiodes can be replaced with photon-number-resolving detectors, which have a smaller dynamics but can measure the light statistics. The resulting new homodyne-like detector acquires a hybrid nature, being it capable of yielding information on both the particle-like (statistics) and wave-like (phase) properties of light signals. The scheme has been tested in the measurement of the quadratures of coherent states, bracket states and phase-averaged coherent states at different intensities of the local oscillator.

scholarly journals Measuring Nonclassicality of Mesoscopic Twin-Beam States with Silicon Photomultipliers †

Proceedings ◽  
2019 ◽  
Vol 12 (1) ◽  
pp. 48
Author(s):  
Giovanni Chesi ◽  
Luca Malinverno ◽  
Alessia Allevi ◽  
Romualdo Santoro ◽  
Massimo Caccia ◽  
...  
Keyword(s):  
Quantum Information ◽  
Quantum Optics ◽  
Output Signal ◽  
Photon Number ◽  
Quantum States ◽  
Silicon Photomultipliers ◽  
Nonclassical Properties ◽  
Relevant Topic ◽  
Twin Beam ◽  
Proper Analysis

The study of nonclassical properties of quantum states is a relevant topic for fundamental Quantum Optics and Quantum Information applications. In the mesoscopic domain, promising results have been obtained using photon-number-resolving detectors. Here we show recent results achieved with the class of Silicon Photomultipliers: by a proper analysis of the output signal, the nonclassicality of twin-beam states can be detected and exploited.

scholarly journals Non-Gaussian quantum states of a multimode light field

2019 ◽  
Vol 16 (2) ◽  
pp. 144-147 ◽  
Author(s):  
Young-Sik Ra ◽  
Adrien Dufour ◽  
Mattia Walschaers ◽  
Clément Jacquard ◽  
Thibault Michel ◽  
...  
Keyword(s):  
Light Field ◽  
Quantum States ◽  
Multimode Light ◽  
Non Gaussian

scholarly journals Optical Bistability in an Optomechanical System with N-Type Atoms under Nonresonant Conditions

Photonics ◽  
2020 ◽  
Vol 7 (4) ◽  
pp. 122
Author(s):  
Yan Gao ◽  
Li Deng ◽  
Aixi Chen
Keyword(s):  
Optical Bistability ◽  
Light Field ◽  
Photon Number ◽  
Optical Switches ◽  
Atomic Ensemble ◽  
Cavity Field ◽  
Bistable Behavior ◽  
Optomechanical System ◽  
The Mean ◽  
Nonlinear Distribution

In this paper, the phenomenon of the optical bistability of a cavity field is theoretically investigated in an optomechanical system containing an N-type atomic ensemble. In this hybrid optomechanical system, the atoms are coupled with two controlling light fields besides coupling with the cavity field. Under the nonresonant condition, we analyze the influences of the coupling strength between cavity and atoms, Rabi frequencies of the controlling light field, the detuning between the controlling light field and atoms, and pump field power on the optical bistable behavior of mean intracavity photon number. The nonlinear distribution of the mean intracavity photon number has a potential application in field optical switches and optical bistable devices.

QUANTIZATION OF REDUCED CHERN–SIMONS GRAVITY WITH A SOURCE

2004 ◽  
Vol 19 (28) ◽  
pp. 4883-4897 ◽  
Author(s):  
A. V. NAZARENKO
Keyword(s):  
Continuous Spectrum ◽  
Degrees Of Freedom ◽  
Equations Of Motion ◽  
Quantum States ◽  
Theory Of Constraints ◽  
Volume Operator ◽  
Modular Transformations ◽  
Probability Of Transition ◽  
Chern Simons

Using the Dirac's theory of constraints, procedure of reduction of field degrees of freedom, whose number is restricted by equations of motion and topological conditions, is proposed. Such a procedure is applied in the case of space with the topology of a torus to the Chern–Simons gravity generalized by inclusion of a source. It is shown that in this system some modular transformations preserving the volume do not lead to physically equivalent states. Such a breaking of modular symmetry reduces the degeneration of quantum states with preservation of continuous spectrum of the volume operator. Probability of transition between spaces of different volumes is computed.

Full mode reconstruction of a light field via a photon-number resolved measurement

2016 ◽  
Author(s):  
I.A. Burenkov ◽  
A.K. Sharma ◽  
T. Gerrits ◽  
G. Harder ◽  
T.J. Bartley ◽  
...  
Keyword(s):  
Light Field ◽  
Photon Number

Statistical reconstruction of optical quantum states based on mutually complementary quadrature quantum measurements

2016 ◽  
Vol 123 (2) ◽  
pp. 212-218 ◽  
Author(s):  
Yu. I. Bogdanov ◽  
G. V. Avosopyants ◽  
L. V. Belinskii ◽  
K. G. Katamadze ◽  
S. P. Kulik ◽  
...  
Keyword(s):  
Quantum Measurements ◽  
Quantum States ◽  
Statistical Reconstruction
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