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Related papers: Phase covariant qubit dynamics and divisibility

200 papers

A dynamical model for quantum channel is introduced which allows one to pass continuously from the memoryless case to the case in which memory effects are present. The quantum and classical communication rates of the model are defined and…

Quantum Physics · Physics 2009-11-11 Vittorio Giovannetti

The question about the existence of so-called ``hidden'' variables in quantum mechanics and the perception of the completeness of quantum mechanics are two sides of the same coin. Quantum analytical mechanics constitutes a completion of…

Quantum Physics · Physics 2026-05-01 Wolfgang Paul

A quantum phase transition is an unequivocal signature of strongly correlated many-body physics. Signatures of such phenomena are yet to be observed in ballistic transport through quantum wires. Recent developments in quantum wires have…

Strongly Correlated Electrons · Physics 2017-07-26 Abolfazl Bayat , Sanjeev Kumar , Michael Pepper , Sougato Bose

We consider the problem of an electron tunneling between two coupled quantum dots, a two-state quantum system (qubit), using a low-transparency point contact (PC) or tunnel junction as a detector continually measuring the position of the…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Hsi-Sheng Goan , Gerard J. Milburn

We revisit qubit-qutrit quantum systems under collective dephasing and answer some of the questions which have not been asked and addressed so far in the literature. In particular, we examine the possibilities of non-trivial phenomena of…

Quantum Physics · Physics 2020-03-03 Mazhar Ali

We study decoherence induced by a dynamic environment undergoing a quantum phase transition. Environment's susceptibility to perturbations - and, consequently, efficiency of decoherence - is amplified near a critical point. Over and above…

Quantum Physics · Physics 2013-05-29 Bogdan Damski , H. T. Quan , Wojciech H. Zurek

The resonant quantum dynamics of an excited two-level emitter is investigated via classical modulation of its transition frequency while simultaneously the radiator interacts with a broadband electromagnetic field reservoir. The frequency…

Quantum Physics · Physics 2015-06-23 Mihai Macovei , Christoph H. Keitel

We review the standard treatment of open quantum systems in relation to quantum entanglement, analyzing, in particular, the behaviour of bipartite systems immersed in a same environment. We first focus upon the notion of complete…

Quantum Physics · Physics 2009-11-11 F. Benatti , R. Floreanini

We construct a dynamical map which is not positive divisible and does not present information backflow either (as measured by trace norm quantifiers). It is formulated for a qutrit system undergoing noninvertible dynamics. This provides an…

Quantum Physics · Physics 2023-01-06 Ángel Rivas

We present a dynamic learning paradigm for "programming" a general quantum computer. A learning algorithm is used to find the control parameters for a coupled qubit system, such that the system at an initial time evolves to a state in which…

Quantum Physics · Physics 2008-08-12 E. C. Behrman , J. E. Steck , P. Kumar , K. A. Walsh

Much of the discussion of decoherence has been in terms of a particle moving in one dimension that is placed in an initial superposition state (a Schr\"{o}dinger "cat" state) corresponding to two widely separated wave packets. Decoherence…

Quantum Physics · Physics 2007-05-23 M. Murakami , G. W. Ford , R. F. O'Connell

The consistent histories formalism can be used to describe histories comprised of events across many systems, times, and places, plausibly rich enough to describe our experiences of the classical world; however, many consistent history sets…

Quantum Physics · Physics 2026-05-11 Nick Ormrod , Tein van der Lugt , Yìlè Yīng , Jarosław K. Korbicz

We consider a continuous measurement of a two-level system (double-dot) by weakly coupled detector (tunnel point contact nearby). While usual treatment leads to the gradual system decoherence due to the measurement, we show that the…

Quantum Physics · Physics 2007-05-23 Alexander N. Korotkov

We study quantum dynamics of many-qubit systems strongly coupled to a quantized electromagnetic cavity mode, in the presence of decoherence and dissipation for both fermions and cavity photons. The analytic solutions are derived for a broad…

Quantum Physics · Physics 2021-09-01 Mikhail Tokman , Qianfan Chen , Maria Erukhimova , Yongrui Wang , Alexey Belyanin

This paper introduces several new classes of mathematical structures that have close connections with physics and with the theory of dynamical systems. The most general of these structures, called indivisible stochastic processes,…

Quantum Physics · Physics 2026-02-09 Jacob A. Barandes

We introduce and investigate an open many-body quantum system in which kinetically constrained coherent and dissipative processes compete. The form of the incoherent dissipative dynamics is inspired by that of epidemic spreading or…

Statistical Mechanics · Physics 2022-10-12 Federico Carollo , Markus Gnann , Gabriele Perfetto , Igor Lesanovsky

Collectively-encoded qubits, involving ensembles of atomic or solid-state emitters, present many practical advantages for quantum technologies. However, they suffer from uncontrolled inhomogeneous dephasing which couples them to a…

Quantum Physics · Physics 2025-11-10 Antoine Covolo , Valentin Magro , Mathieu Girard , Sébastien Garcia , Alexei Ourjoumtsev

Dynamical quantum phase transitions (DQPTs) are non-equilibrium transitions characterized by the orthogonality between an initial quantum state and its time-evolved counterpart following a sudden quench. Recently, studies of this phenomenon…

Quantum Physics · Physics 2026-05-27 Kai Zhang , Chang Shu , Kai Sun

We present a theory for the two kinds of dynamical quantum phase transitions, termed DPT-I and DPT-II, based on a minimal set of symmetry assumptions. In the special case of collective systems with infinite-range interactions, both are…

Statistical Mechanics · Physics 2023-03-10 Ángel L. Corps , Armando Relaño

Every open-system dynamics can be associated to infinitely many stochastic pictures, called unravelings, which have proved to be extremely useful in several contexts, both from the conceptual and the practical point of view. Here, focusing…

Quantum Physics · Physics 2022-10-19 Dariusz Chruściński , Kimmo Luoma , Jyrki Piilo , Andrea Smirne