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Related papers: Time Optimal Control of Coupled Qubits Under Non-S…

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Coherent controlization, i.e., coherent conditioning of arbitrary single- or multi-qubit operations on the state of one or more control qubits, is an important ingredient for the flexible implementation of many algorithms in quantum…

Quantum Physics · Physics 2015-12-16 Nicolai Friis , Alexey A. Melnikov , Gerhard Kirchmair , Hans J. Briegel

We study decoherence of propagating spin-1/2 excitations in generic (non-integrable and/or disordered) spin chains. We find the relevant decoherence times to be shorter in both the near-critical and diffusive regimes (if any), which fact…

Strongly Correlated Electrons · Physics 2009-11-10 D. V. Khveshchenko

We theoretically demonstrate that nuclear spins can be harnessed to coherently control two-electron spin states in a double quantum dot. Hyperfine interactions lead to an avoided crossing between the spin singlet state and the ms = +1…

Mesoscale and Nanoscale Physics · Physics 2011-12-21 Hugo Ribeiro , J. R. Petta , Guido Burkard

Spin dynamics of a cluster of coupled spins 1/2 can be manipulated to store and process a large amount of information. A new type of dynamic response makes it possible to excite coherent long-living signals, which can be used for exchanging…

Quantum Physics · Physics 2015-06-26 A. K. Khitrin , V. L. Ermakov , B. M. Fung

It is suggested to map the qubits into solid state NMR spin system collective states instead of the states of the individual spin. Such an approach introduces the stable computational basis without any additional actions and allows to…

Quantum Physics · Physics 2007-05-23 Alexander R. Kessel , Vladimir L. Ermakov

We investigate the performance of dynamical decoupling methods at suppressing electron spin decoherence from a low-temperature nuclear spin reservoir in a quantum dot. The controlled dynamics is studied through exact numerical simulation,…

Mesoscale and Nanoscale Physics · Physics 2009-11-13 Wenxian Zhang , V. V. Dobrovitski , Lea F. Santos , Lorenza Viola , B. N. Harmon

We study feedback control for discrete-time linear time-invariant systems in the presence of quantization both in the control action and in the measurement of the controlled variable. While in some application the quantization effects can…

Systems and Control · Computer Science 2020-05-12 Alessandro Vittorio Papadopoulos , Federico Terraneo , Alberto Leva , Maria Prandini

he multiqubit entangled states are coherently controlled in the quantum spin systems composed of $N+1$ interacting antiferromagnetic molecular rings. The tunable intermolecular couplings arise from the local exchange interactions between…

Quantum Physics · Physics 2009-03-17 Xiang Hao , Tao Pan , Taocheng Zang , Shiqun Zhu

Optical half-wave microresonators enable to control the optical mode density around a quantum system and thus to modify the temporal emission properties. If the coupling rate exceeds the damping rate, strong coupling between a…

Spin-orbit coupling fundamentally alters spin qubits, opening pathways to improve the scalability of quantum computers via long distance coupling mediated by electric fields, photons, or phonons. It also allows for new engineered hybrid and…

We construct a mixed spin 1/2 and $S$ integrable model and investigate its finite size properties. For a certain conformal invariant mixed spin system the central charge can be decomposed in terms of the conformal anomaly of two single…

Statistical Mechanics · Physics 2009-10-30 S. R. Aladim , M. J. Martins

It is shown that the full unknown state of a spin-1/2 system, S, which, within Born's statistical interpretation, is meant as the state of an ensamble of identically prepared systems, can be determined with a simultaneous measurement with…

Quantum Physics · Physics 2017-08-23 G. Aquino , B. Mehmani

We study the motion of a charged quantum particle, constrained on the surface of a cylinder, in the presence of a radial magnetic field. When the spin of the particle is neglected, the system essentially reduces to an infinite family of…

Quantum Physics · Physics 2007-05-23 C. Chryssomalakos , A. Franco , A. Reyes-Coronado

We report the realization of a robust and highly controllable two-dimensional (2D) spin-orbit (SO) coupling with topological non-trivial band structure. By applying a retro-reflected 2D optical lattice, phase tunable Raman couplings are…

Monitored quantum circuits exhibit entanglement transitions at certain measurement rates. Such a transition separates phases characterized by how much information an observer can learn from the measurement outcomes. We study SU(2)-symmetric…

Non-equilibrium dynamics of many-body systems is important in many branches of science, such as condensed matter, quantum chemistry, and ultracold atoms. Here we report the experimental observation of a phase transition of the quantum…

Quantum Physics · Physics 2015-09-24 Gonzalo A. Alvarez , Dieter Suter , Robin Kaiser

Recently, synthetic spin-orbit coupling has been introduced into cold-atom systems for more flexible control of the Hamiltonian, which was further made time-varying through two-photon detuning to achieve dynamic control of the cold-atom…

Quantum Physics · Physics 2024-03-05 Dong Liu , Zejian Ren , Wai Chun Wong , Entong Zhao , Chengdong He , Ka Kwan Pak , Gyu-Boong Jo , Jensen Li

For control systems in discrete time, this paper discusses measure-theoretic invariance entropy for a subset Q of the state space with respect to a quasi-stationary measure obtained by endowing the control range with a probability measure.…

Dynamical Systems · Mathematics 2018-04-05 Fritz Colonius

We propose a new approach to the measurement of a single spin state, based on nuclear magnetic resonance (NMR) techniques and inspired by the coherent control over many-body systems envisaged by Quantum Information Processing (QIP). A…

We study the effect of spin-orbit coupling on quantum gates produced by pulsing the exchange interaction between two single electron quantum dots. Spin-orbit coupling enters as a small spin precession when electrons tunnel between dots. For…

Mesoscale and Nanoscale Physics · Physics 2016-08-31 D. Stepanenko , N. E. Bonesteel , D. P. DiVincenzo , G. Burkard , Daniel Loss