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Related papers: A quantum measurement of the spin direction

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We address the problem of sensing the curvature of a manifold by performing measurements on a particle constrained to the manifold itself. In particular, we consider situations where the dynamics of the particle is quantum mechanical and…

Quantum Physics · Physics 2019-10-02 Daniele Bonalda , Luigi Seveso , Matteo G. A. Paris

We have developed a novel technique for detection of spin polarization with a quantum dot weakly coupled to the objective device. The disturbance to the object in this technique is very small since the detection is performed through…

Mesoscale and Nanoscale Physics · Physics 2016-12-21 Sunwoo Kim , Yoshiaki Hashimoto , Taketomo Nakamura , Shingo Katsumoto

We consider the problem of tunneling between two leads via a localized spin 1/2 or any other microscopic system which can be modeled by a two-level Hamiltonian. We assume that a constant magnetic field ${\bf B}_0$ acts on the spin, that…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 L. N. Bulaevskii , M. Hruška , G. Ortiz

We consider an ensemble of trapped atoms interacting with a continuous wave laser field. For sufficiently polarized atoms and for a polarized light field, we may approximate the non-classical components of the collective spin angular…

Quantum Physics · Physics 2009-11-10 Lars Bojer Madsen , Klaus Mølmer

The conventional view, that Einstein was wrong to believe that quantum physics is local and deterministic, is challenged. A parametrised model, Q, for the state vector evolution of spin 1/2 particles during measurement is developed. Q draws…

Quantum Physics · Physics 2008-02-03 T. N. Palmer

Measurement-based quantum computation is different from other approaches for quantum computation, in that everything needs to be done is only local measurement on a certain entangled state. It thus uses entanglement as the resource that…

Quantum Physics · Physics 2021-09-22 Tzu-Chieh Wei

Recent advances in transmission electron microscopy (TEM) have opened the path toward spin resonance spectroscopy with single-spin sensitivity. To assess this potential, we investigate the quantum precision limits for sensing magnetic…

We study the physics of a magnetic molecule described by a "giant" spin with multiple ($d > 2$) spin states interacting with the quantized cavity field produced by a superconducting resonator. By means of the input-output formalism, we…

Quantum Physics · Physics 2022-06-17 Álvaro Gómez-León , Fernando Luis , David Zueco

We show that dynamics in spin-orbit coupling field simulates the von Neumann measurement of a particle spin. We demonstrate how the measurement influences the spin and coordinate evolution of a particle by comparing two examples of such a…

Quantum Physics · Physics 2014-01-21 E. Ya. Sherman , D. Sokolovski

This paper reviews quantum spin squeezing, which characterizes the sensitivity of a state with respect to an SU(2) rotation, and is significant for both entanglement detection and high-precision metrology. We first present various…

Quantum Physics · Physics 2011-11-29 Jian Ma , Xiaoguang Wang , C. P. Sun , Franco Nori

A hamiltonian model is solved, which satisfies all requirements for a realistic ideal quantum measurement. The system S is a spin-$\half$, whose $z$-component is measured through coupling with an apparatus A=M+B, consisting of a magnet…

Statistical Mechanics · Physics 2016-08-31 Armen E. Allahverdyan , Roger Balian , Theo M. Nieuwenhuizen

This review describes the physics of spins in quantum dots containing one or two electrons, from an experimentalist's viewpoint. Various methods for extracting spin properties from experiment are presented, restricted exclusively to…

Mesoscale and Nanoscale Physics · Physics 2011-11-09 R. Hanson , L. P. Kouwenhoven , J. R. Petta , S. Tarucha , L. M. K. Vandersypen

Two-electron charged self-assembled quantum dot molecules exhibit a decoherence-avoiding singlet-triplet qubit subspace and an efficient spin-photon interface. Here, we demonstrate that the cycling transitions originating from auxiliary…

Mesoscale and Nanoscale Physics · Physics 2015-09-15 Y. L. Delley , M. Kroner , S. Faelt , W. Wegscheider , A. İmamoğlu

This article presents numerical recipes for simulating high-temperature and non-equilibrium quantum spin systems that are continuously measured and controlled. The notion of a spin system is broadly conceived, in order to encompass…

The first order quantum correction to the power of spontaneous radiation of electrons in an arbitrary two-component periodic magnetic field was obtained. The phenomenon of selfpolarization of the spin of electrons in a process of…

Quantum Physics · Physics 2007-05-23 V. G. Bagrov , V. V. Belov , M. M. Nikitin , A. Yu. Trifonov

The spin of a single electron confined in a semiconductor quantum dot is a natural qubit candidate. Fundamental building blocks of spin-based quantum computing have been demonstrated in double quantum dots with significant spin-orbit…

Mesoscale and Nanoscale Physics · Physics 2024-07-23 Aritra Sen , György Frank , Baksa Kolok , Jeroen Danon , András Pályi

A distinguishing feature of protective measurement is the possibility of obtaining information about expectation values while making the disturbance of the initial state arbitrarily small. Quantifying this state disturbance is of paramount…

Quantum Physics · Physics 2015-12-10 Maximilian Schlosshauer

We investigate the maximum signal to noise ratio per unit time that can be achieved for a spin 1/2 particle subjected to a periodic pulse sequence. Optimal control techniques are applied to design the control field and the position of the…

Quantum Physics · Physics 2015-06-22 M. Lapert , E. Assémat , S. J. Glaser , D. Sugny

Entanglement can improve the measurement precision of quantum sensors beyond the shot noise limit. Neutral atoms, the basis of some of the most precise and accurate optical clocks and interferometers, do not naturally exhibit all-to-all…

We demonstrate a coherent quantum measurement for the determination of the degree of polarization (DOP). This method allows to measure the DOP in the presence of fast polarization state fluctuations, difficult to achieve with the typically…

Quantum Physics · Physics 2009-11-10 M. Legre , M. Wegmuller , N. Gisin