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Related papers: A Quantum Anti-Zeno Paradox

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The decay of any unstable quantum state can be inhibited or enhanced by carefully tailored measurements, known as the quantum Zeno effect (QZE) or anti-Zeno effect (QAZE). To date, studies of QZE (QAZE) transitions have since expanded to…

Quantum Physics · Physics 2023-07-06 Jiaming Li , Tishuo Wang , Le Luo , Sreya Vemuri , Yogesh N Joglekar

The absolute separability problem asks for a characterization of the quantum states $\rho \in M_m\otimes M_n$ with the property that $U\rho U^\dagger$ is separable for all unitary matrices $U$. We investigate whether or not it is the case…

Quantum Physics · Physics 2015-04-16 Srinivasan Arunachalam , Nathaniel Johnston , Vincent Russo

The Zeno effect, in which repeated observation freezes the dynamics of a quantum system, stands as an iconic oddity of quantum mechanics. When a measurement is unable to distinguish between states in a subspace, the dynamics within that…

For an ergodic system, the time average of a classical observable coincides with that obtained via the Liouville probability density, a delta-function on the energy shell. Reinterpreting this distribution as a Wigner function, that is, the…

Quantum Physics · Physics 2015-06-19 Alfredo M. Ozorio de Almeida

A new quantum-stochastic differential calculus is derived for representing continuous quantum measurement of the position operator. Closed nonlinear quantum-stochastic differential equation is given for the quantum state of the observed…

Quantum Physics · Physics 2019-01-01 Lajos Diósi

Measurement quantum mechanics, the theory of a quantum system which undergoes a measurement process, is introduced by a loop of mathematical equivalencies connecting previously proposed approaches. The unique phenomenological parameter of…

Condensed Matter · Physics 2009-10-28 Carlo Presilla , Roberto Onofrio , Ubaldo Tambini

We show that the Quantum Zeno Effect prevails even if the entanglement with the measuring probe is not complete. The dynamics towards the asymptotic regime as a function of $N$, the number of measurements, reveals surprising results: the…

Quantum Physics · Physics 2012-08-07 R. Rossi , A. R. Bosco de Magalhaes , M. C. Nemes

It is shown that Quantum Mechanics is ambiguous when predicting relative frequencies for an entangled system if the measurements of both subsystems are performed in spatially separated events. This ambiguity gives way to unphysical…

Quantum Physics · Physics 2016-01-27 Carlos Lopez

Quantum mechanics of a particle in an infinite square well under the influence of a time-dependent electric field is reconsidered. In some gauge, the Hamiltonian depends linearly on the momentum operator which is symmetric but not…

Quantum Physics · Physics 2007-05-23 Stefan Weigert

Classically general covariance is found from the idea that a vector is a physical quantity which exists independently of choice of coordinate system and is unchanged by a change of coordinate system. It is often assumed that there exists…

General Relativity and Quantum Cosmology · Physics 2007-05-23 Charles Francis

We show that the orthogonal projection operator onto the range of the adjoint of a linear operator $T$ can be represented as $UT,$ where $U$ is an invertible linear operator. Using this representation we obtain a decomposition of a Normal…

Statistics Theory · Mathematics 2018-02-09 Rajeshwari Majumdar , Suman Majumdar

We consider strangeness correlations of the EPR type in K^0 \bar{K}^0 pairs created in a J^{PC} = 1^{--} state as a function of time under the hypothesis that spontaneous decoherence takes place. We parameterize the degree of decoherence by…

High Energy Physics - Phenomenology · Physics 2009-10-31 R. A. Bertlmann , W. Grimus , B. C. Hiesmayr

We provide a reinterpretation of the quantum vacuum ambiguities that one encounters when studying particle creation phenomena due to an external and time-dependent agent. We propose a measurement-motivated understanding: Each way of…

Kiukas, Lahti and Ylinen asked the following general question. When is a positive operator measure projection valued? A version of this question formulated in terms of operator moments was posed in a recent paper of the present authors. Let…

Functional Analysis · Mathematics 2025-08-13 Paweł Pietrzycki , Jan Stochel

We consider the problem of determining the state of a quantum system given one or more readings of the expectation value of an observable. The system is assumed to be a finite dimensional quantum control system for which we can influence…

Quantum Physics · Physics 2009-11-10 Domenico D'Alessandro

Probabilities of the outcomes of consecutive quantum measurements can be obtained by construction probability amplitudes, thus implying unitary evolution of the measured system, broken each time a measurement is made. In practice, the…

Quantum Physics · Physics 2022-07-13 D. Sokolovski

If the unitary quantum mechanical state evolution is universally valid, quantized systems evolve uniformly, deterministically, and reversible; that is, one-to-one. Hence, what is considered an irreversible measurement might be a purely…

Quantum Physics · Physics 2011-02-16 Karl Svozil

Everett's interpretation of quantum mechanics was proposed to avoid problems inherent in the prevailing interpretational frame. It assumes that quantum mechanics can be applied to any system and that the state vector always evolves…

Quantum Physics · Physics 2017-05-03 Louis Marchildon

Nonlinear quantum optical systems are of paramount relevance for modern quantum technologies, as well as for the study of dissipative phase transitions. Their nonlinear nature makes their theoretical study very challenging and hence they…

Quantum Physics · Physics 2015-06-03 Peter Degenfeld-Schonburg , Carlos Navarrete-Benlloch , Michael J. Hartmann

An exact invariant operator of time-dependent coupled oscillators is derived using the Liouville-von Neumann equation. The unitary relation between this invariant and the invariant of two uncoupled simple harmonic oscillators is…

Quantum Physics · Physics 2022-10-17 Jeong Ryeol Choi