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Spin networks are endowed with an Information Transfer Fidelity (ITF), which defines an absolute upper bound on the probability of transmission of an excitation from one spin to another. The ITF is easily computable but the bound can be…

Quantum Physics · Physics 2015-10-12 Edmond Jonckheere , Frank Langbein , Sophie Schirmer

Quantum teleportation should surpass maximum fidelity thresholds possible with local measurements and classical communications. Benchmarks have been established when states are drawn from a uniform distribution of qubits or coherent states…

Quantum Physics · Physics 2026-05-26 Tomáš Opatrný , Allison Brattley , Kunal K. Das

Quantum state discrimination is a fundamental concept in quantum information theory, which refers to a class of techniques to identify a specific quantum state through a positive operator-valued measure. In this work, we investigate how…

Quantum Physics · Physics 2025-07-09 Hyunho Cha , Jungwoo Lee

In this work, we use the Hamiltonian of a modified Dzyaloshinskii-Moriya model and investigate the perfect transfer of the quantum state on the spin networks. In this paper, we calculate fidelity in which fidelity depends on magnetic field…

Quantum Physics · Physics 2010-10-04 S. Salimi , B. Ghavami , Arash Sorouri

This paper is concerned with the partial information optimal control problem of mean-field type under partial observation, where the system is given by a controlled mean-field forward-backward stochastic differential equation with…

Optimization and Control · Mathematics 2017-08-21 Qingxin Meng , Qiuhong Shi , Maoning Tang

In the case of quantum systems interacting with multiple environments, the time-evolution of the reduced density matrix is described by the Liouvillian. For a variety of physical observables, the long-time limit or steady state solution is…

Quantum Physics · Physics 2022-01-05 Rodrigo A. Vargas-Hernández , Ricky T. Q. Chen , Kenneth A. Jung , Paul Brumer

A quantum network requires information transfer between distant quantum computers, which would enable distributed quantum information processing and quantum communication. One model for such a network is based on the probabilistic…

Quantum Physics · Physics 2015-06-12 A. Stute , B. Casabone , B. Brandstätter , K. Friebe , T. E. Northup , R. Blatt

We study quantum state transfer through a qubit network modeled by spins with XY interaction, when relying on a single excitation. We show that it is possible to achieve perfect transfer by shifting (adding) energy to specific vertices.…

Quantum Physics · Physics 2010-01-20 Andrea Casaccino , Seth Lloyd , Stefano Mancini , Simone Severini

The optimal quantum control theory is employed to determine electric pulses capable of producing quantum gates with high fidelity (higher than 0.9997). Particularly, these quantum gates were chosen to perform the permutation algorithm (Z.…

Quantum Physics · Physics 2018-03-28 C. M. Rivera-Ruiz , E. F. de Lima , F. F. Fanchini , V. Lopez-Richard , L. K. Castelano

Quantum states can be used to encode the information contained in a direction, i.e., in a unit vector. We present the best encoding procedure when the quantum state is made up of $N$ spins (qubits). We find that the quality of this optimal…

Quantum Physics · Physics 2009-11-06 E. Bagan , M. Baig , A. Brey , R. Munoz-Tapia , R. Tarrach

Despite significant progress in theoretical and laboratory quantum control, engineering quantum systems remains principally challenging due to manifestation of noise and uncertainties associated with the field and Hamiltonian parameters. In…

Quantum Physics · Physics 2021-12-15 Andrew Koswara , Vaibhav Bhutoria , Raj Chakrabarti

We prove a Pontryagin Maximum Principle for optimal control problems in the space of probability measures, where the dynamics is given by a transport equation with non-local velocity. We formulate this first-order optimality condition using…

Optimization and Control · Mathematics 2020-02-28 Benoît Bonnet , Francesco Rossi

We propose a scheme for quantum state transfer(QST) between two qubits which is based on their individual interaction with a common boson environment. The corresponding single mode spin-boson Hamiltonian is solved by mapping it onto a wave…

Quantum Physics · Physics 2009-11-13 Yue Yin , S. N. Evangelou

We use optimal control theory to construct external electric fields which coherently transfer the electronic charge in a double quantum-dot system. Without truncation of the eigenstates we operate on desired superpositions of the states in…

Quantum Physics · Physics 2015-05-19 A. Putaja , E. Rasanen

The ability to transfer quantum information from one location to another with high fidelity is of central importance to quantum information science. Unfortunately for the simplest system of a uniform chain (a spin chain or a particle in a…

Quantum Gases · Physics 2016-01-28 Xining Chen , Robert Mereau , David L. Feder

Fidelity is a fundamental and ubiquitous concept in quantum information theory. Fuchs-van de Graaf's inequalities deal with bounding fidelity from above and below. In this paper, we give a lower bound on the quantum fidelity between two…

Quantum Physics · Physics 2016-04-06 Lin Zhang , Kaifeng Bu , Junde Wu

The goal in quantum state transfer is to avoid the need to physically transport carriers of quantum information. This is achieved by using a suitably engineered Hamiltonian that induces the transfer of the state of one subsystem to another.…

Quantum teleportation is one of the essential primitives of quantum communication. We suggest that any quantum teleportation scheme can be characterized by its efficiency, i.e. how often it succeeds to teleport, its fidelity, i.e. how well…

Quantum Physics · Physics 2015-06-26 Dik Bouwmeester , Jian-Wei Pan , Harald Weinfurter , Anton Zeilinger

The importance of feedback control is being increasingly appreciated in quantum physics and applications. This paper describes the use of optimal control methods in the design of quantum feedback control systems, and in particular the paper…

Quantum Physics · Physics 2009-11-10 M. R. James

Ultrastrong coupling may allow faster operations for the development of quantum technologies at the expenses of increased sensitivity to new kind of intrinsic errors. We study state transfer in superconducting circuit QED architectures in…