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Related papers: Flag-Based Control of Quantum Purity for $n=2$ Sys…

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We show that, taking a two-dimensional photonic-crystal slab system as an example, surprisingly high quality factors (Q) over 10^5 are achievable, even in the absence of a rigorous photonic-band-gap. We find that the density of in-plane…

Optics · Physics 2015-06-11 Se-Heon Kim , Andrew Homyk , Sameer Walavalkar , Axel Scherer

The mesoscopic properties of a plasma in a cylindrical magnetic field are investigated from the view point of test-particle dynamics. When the system has enough time and spatial symmetries, a Hamiltonian of a test particle is completely…

Plasma Physics · Physics 2019-09-19 Shun Ogawa , Xavier Leoncini , Alexei Vasiliev , Xavier Garbet

The article considers a two-level open quantum system, whose evolution is governed by the Gorini--Kossakowski--Lindblad--Sudarshan master equation with Hamiltonian and dissipation superoperator depending, correspondingly, on piecewise…

Quantum Physics · Physics 2021-06-21 Oleg V. Morzhin , Alexander N. Pechen

Scaling up superconducting quantum processors with optimized performance requires a sufficient flexibility in the choice of operating points for single and two qubit gates to maximize their fidelity and cope with imperfections. Flux control…

Quantum Physics · Physics 2019-12-20 Nicolas Didier

The linear convex log-homotopy has been used in the derivation of particle flow filters. One natural question is whether it is beneficial to consider other forms of homotopy. We revisit this question by considering a general linear form of…

Optimization and Control · Mathematics 2021-07-13 Liyi Dai , Frederick E. Daum

We analyze the phase diagram of N=4 supersymmetric Yang-Mills theory with fundamental matter in the presence of a background magnetic field and nonzero baryon number. We identify an isolated quantum critical point separating two differently…

High Energy Physics - Theory · Physics 2015-05-18 Kristan Jensen , Andreas Karch , Ethan G. Thompson

Quantum coherence inherently affects the dynamics and the performances of a quantum machine. Coherent control can, at least in principle, enhance the work extraction and boost the velocity of evolution in an open quantum system. Using…

Quantum Physics · Physics 2018-12-10 Vasco Cavina , Andrea Mari , Alberto Carlini , Vittorio Giovannetti

The precise implementation and manipulation of quantum gates is key to extracting advantages from future quantum technologies. Achieving this requires very accurate control over the quantum system. If one has complete knowledge about a…

Quantum Physics · Physics 2025-03-21 Anirban Dey , Mattias T. Johnsson , Daniel Burgarth

We solve the problem of minimizing the number of critical points among all functions on a surface within a prescribed distance {\delta} from a given input function. The result is achieved by establishing a connection between discrete Morse…

Computational Geometry · Computer Science 2015-05-07 Ulrich Bauer , Carsten Lange , Max Wardetzky

We study a double quantum dot in the regime where each dot carries a spin-1/2. This system is described by the 2-impurity Kondo model, having a non-Fermi liquid fixed point for a critical value of the inter-impurity coupling. The…

Mesoscale and Nanoscale Physics · Physics 2015-05-13 Eran Sela , Ian Affleck

A Markovian master equation describing the evolution of open quantum systems in the presence of a time-dependent external field is derived within the Bloch-Redfield formalism. It leads to a system--bath interaction which depends on the…

Mesoscale and Nanoscale Physics · Physics 2009-11-11 H. Jirari , W. Pötz

Conventional approaches for controlling open quantum systems use coherent control which affects the system's evolution through the Hamiltonian part of the dynamics. Such control, although being extremely efficient for a large variety of…

Quantum Physics · Physics 2009-05-04 Alexander Pechen , Herschel Rabitz

We study the possibility of deterministic protocols for extracting work from quantum systems. Focusing on the two-point measurement work extraction scenario, we prove that, with enough copies of the system, such zero-fluctuation protocols…

Quantum Physics · Physics 2024-07-15 Raffaele Salvia , Vittorio Giovannetti

Quantum state tomography and other measures of the global properties of a quantum state are indispensable tools in understanding many body physics through quantum simulators. Unfortunately, the number of experimental measurements of the…

Quantum Physics · Physics 2021-06-16 Yariv Yanay , Charles Tahan

Continuously monitoring the environment of a quantum many-body system reduces the entropy of (purifies) the reduced density matrix of the system, conditional on the outcomes of the measurements. We show that, for mixed initial states, a…

Quantum Physics · Physics 2020-11-03 Michael J. Gullans , David A. Huse

By properly generalizing Nozie`res' Fermi liquid theory, we construct an Hamiltonian approach to the scattering of conduction electrons off a spin-1/2 impurity in the ovescreneed Kondo regime, as T -> 0. We derive the S-matrix at the…

Mesoscale and Nanoscale Physics · Physics 2009-11-10 Domenico Giuliano , Arturo Tagliacozzo

In this article we investigate the controllability for neutral stochastic functional integro-differential equations with finite delay, driven by a fractional Brownian motion with Hurst parameter lesser than $1/2$ in a Hilbert space. We…

Probability · Mathematics 2018-09-26 Brahim Boufoussi , Soufiane Mouchtabih

In this work, we investigate how and to which extent a quantum system can be driven along a prescribed path in Hilbert space by a suitably shaped laser pulse. To calculate the optimal, i.e., the variationally best pulse, a properly defined…

Quantum Physics · Physics 2007-05-23 I. Serban , J. Werschnik , E. K. U. Gross

Many-body open quantum systems balance internal dynamics against decoherence from interactions with an environment. Here, we explore this balance via random quantum circuits implemented on a trapped ion quantum computer, where the system…

We develop a general optimization strategy for performing a chosen unitary or non-unitary task on an open quantum system. The goal is to design a controlled time-dependent system Hamiltonian by variationally minimizing or maximizing a…

Quantum Physics · Physics 2016-03-29 Jens Clausen , Guy Bensky , Gershon Kurizki