English
Related papers

Related papers: Dephasing of quantum bits by a quasi-static mesosc…

200 papers

Complex environments, such as molecular matrices and biological material, play a fundamental role in many important dynamic processes in condensed phases. Because it is extremely difficult to conduct full quantum dynamics simulations on…

Quantum Physics · Physics 2022-01-03 Kiyoto Nakamura , Yoshitaka Tanimura

The quantum nature of a microscopic system can only be revealed when it is sufficiently decoupled from surroundings. Interactions with the environment induce relaxation and decoherence that turn the quantum state into a classical mixture.…

Mesoscale and Nanoscale Physics · Physics 2017-09-12 Alexey M. Shakirov , Alexey N. Rubtsov , Alexander I. Lichtenstein , Pedro Ribeiro

We report on the immersion of a spin-qubit encoded in a single trapped ion into a spin-polarized neutral atom environment, which possesses both continuous (motional) and discrete (spin) degrees of freedom. The environment offers the…

Quantum Physics · Physics 2014-07-24 L. Ratschbacher , C. Sias , L. Carcagni , J. M. Silver , C. Zipkes , M. Köhl

We investigate decoherence due to pure dephasing of a localized spin qubit interacting with a nuclear spin bath. Although in the limit of a very large magnetic field the only decoherence mechanism is spectral diffusion due to dipolar…

Mesoscale and Nanoscale Physics · Physics 2009-06-18 L. Cywinski , W. M. Witzel , S. Das Sarma

A complete treatment of the entanglement of two-level systems, which evolves through the contact with a thermal bath, must include the fact that the system and the bath are not fully separable. Therefore, quantum coherent superpositions of…

Quantum Physics · Physics 2015-05-18 Arend G. Dijkstra , Yoshitaka Tanimura

We consider the motion of a particle, taking into account its interaction with environmental degrees of freedom. The dephasing time is determined by the nature of the environment, and depends on the particle velocity. Our interest is in the…

Mesoscale and Nanoscale Physics · Physics 2009-11-07 Doron Cohen

Engineering, controlling, and simulating quantum dynamics is a strenuous task. However, these techniques are crucial to develop quantum technologies, preserve quantum properties, and engineer decoherence. Earlier results have demonstrated…

We present an approach that allows quantifying decoherence processes in an open quantum system subject to external time-dependent control. Interactions with the environment are modeled by a standard bosonic heat bath. We develop two…

Mesoscale and Nanoscale Physics · Physics 2010-10-12 Dmitry Solenov , Vladimir Privman

Coherence in an open quantum system is degraded through its interaction with a bath. This decoherence can be avoided by restricting the dynamics of the system to special decoherence-free subspaces. These subspaces are usually constructed…

Quantum Physics · Physics 2016-09-08 Daniel A. Lidar , Dave Bacon , Julia Kempe , K. B. Whaley

We determine the total state dynamics of a dephasing open quantum system using the standard environment of harmonic oscillators. Of particular interest are random unitary approaches to the same reduced dynamics and system-environment…

Quantum Physics · Physics 2015-06-04 Ansgar Pernice , Julius Helm , Walter T. Strunz

We numerically investigate decoherence of a two-spin system (central system) by a bath of many spins 1/2. By carefully adjusting parameters, the dynamical regime of the bath has been varied from quantum chaos to regular, while all other…

Quantum Physics · Physics 2009-11-10 J. Lages , V. V. Dobrovitski , B. N. Harmon

We consider coupled quantum two-state systems (qubits) exposed to a global relaxation process. The global relaxation refers to the assumption that qubits are coupled to the same quantum bath with approximately equal strengths, appropriate…

Mesoscale and Nanoscale Physics · Physics 2007-10-03 T. Ojanen , A. O. Niskanen , Y. Nakamura , A. A. Abdumalikov

We consider a spin-$j$ particle coupled to a structured bath of bosonic modes that decay into thermal baths. We obtain an analytic expression for the reduced spin state and use it to investigate non-Markovian spin dynamics. In the heavily…

Quantum Physics · Physics 2022-04-06 Mattias T. Johnsson , Ben Q. Baragiola , Thomas Volz , Gavin K. Brennen

Coupling with an external environment inevitably affects the dynamics of a quantum system. Here, we consider how charging performances of a quantum battery, modelled as a two level system, are influenced by the presence of an Ohmic thermal…

Mesoscale and Nanoscale Physics · Physics 2020-09-03 Matteo Carrega , Alba Crescente , Dario Ferraro , Maura Sassetti

In a two-qubit system the coupling with an environment affects considerably the entanglement dynamics, and usually leads to the loss of entanglement within a finite time. Since entanglement is a key feature in the application of such…

Quantum Physics · Physics 2009-11-13 Y. Dubi , M. Di Ventra

We revisit decoherence process of a qubit register interacting with a thermal bosonic bath. We generalize the previous studies by considering not only the register's behavior but also of a part of its environment. In particular, we are…

Quantum Physics · Physics 2019-02-25 Jan Tuziemski , Aniello Lampo , Maciej Lewenstein , Jarosław K. Korbicz

We investigate in detail, using both analytical and numerical tools, the decoherence of electron spins in quantum dots (QDs) coupled to a bath of nuclear spins in magnetic fields or with various initial bath polarizations, focusing on the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 Wenxian Zhang , V. V. Dobrovitski , K. A. Al-Hassanieh , E. Dagotto , B. N. Harmon

Molecular nanomagnets are quantum spin systems potentially serving as qudits for future quantum technologies thanks to their many accessible low-energy states. At low temperatures, the primary source of error in these systems is pure…

We address the dynamics of a qubit interacting with a quasi static random classical field having both a longitudinal and a transverse component and described by a Gaussian stochastic process. In particular, we analyze in details the…

Quantum Physics · Physics 2014-05-06 Claudia Benedetti , Matteo G. A. Paris

Interaction of solid state qubits with environmental degrees of freedom strongly affects the qubit dynamics, and leads to decoherence. In quantum information processing with solid state qubits, decoherence significantly limits the…

Mesoscale and Nanoscale Physics · Physics 2010-02-26 Luca Chirolli , Guido Burkard