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Related papers: General Quantum State Swap: an XY model analysis

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We introduce and study peak state transfer, a notion of high state transfer in qubit networks modeled by continuous-time quantum walks. Unlike perfect or pretty good state transfer, peak state transfer does not require fidelity arbitrarily…

Quantum Physics · Physics 2025-10-02 Gabriel Coutinho , Krystal Guo , Vincent Schmeits

Precision control of a quantum system requires accurate determination of the effective system Hamiltonian. We develop a method for estimating the Hamiltonian parameters for some unknown two-state system and providing uncertainty bounds on…

The transfer of quantum states has played an important role in quantum information processing. In fact, transfer of quantum states from point $A$ to $B$ with unit fidelity is very important for us and we focus on this case. In recent years,…

Quantum Physics · Physics 2014-06-24 S. Salimi , S. Ghoraishipour , A. Sorouri

In the present paper, a novel bidirectional quantum teleportation protocol is proposed. By using entanglement swapping technique, two GHZ states are shared as a quantum channel between Alice and Bob as legitimate users. In this scheme,…

Quantum Physics · Physics 2014-11-04 Shima Hassanpour , Monireh Houshmand

We present a systematic analysis of quantum Heisenberg-, XY- and interchange models on the complete graph. These models exhibit phase transitions accompanied by spontaneous symmetry breaking, which we study by calculating the generating…

Mathematical Physics · Physics 2021-06-30 Jakob E. Björnberg , Jürg Fröhlich , Daniel Ueltschi

The ESR model proposes a new theoretical perspective which incorporates the mathematical formalism of standard (Hilbert space) quantum mechanics (QM) in a noncontextual framework, reinterpreting quantum probabilities as conditional on…

Quantum Physics · Physics 2015-06-15 Sandro Sozzo

We investigate a system composed of $N$ coupled cavities and two-level atoms interacting one at a time. Adjusting appropriately the atom-field detuning, and make the hopping rate of photons between neighboring cavities, $A$, greater than…

Quantum Physics · Physics 2010-08-23 Bruno F. C. Yabu-uti , José A. Roversi

For any pair of quantum states (the hypotheses), the task of binary quantum hypotheses testing is to derive the tradeoff relation between the probability $p_{01}$ of rejecting the null hypothesis and $p_{10}$ of accepting the alternative…

Quantum Physics · Physics 2020-09-16 Le Phuc Thinh , Michele Dall'Arno , Valerio Scarani

We present a general formalism to the problem of perfect state-transfer (PST), where the state involves multiple excitations of the quantum network. A key feature of our formalism is that it allows for inclusion of nontrivial interactions…

Quantum Physics · Physics 2011-08-04 T. Brougham , G. M. Nikolopoulos , I. Jex

We consider the task of deciding whether an unknown qubit state falls in a prescribed neighborhood of a reference state. We assume that several copies of the unknown state are given and apply a unitary operation pairwise on them combined…

Quantum Physics · Physics 2018-08-27 Orsolya Kálmán , Tamás Kiss

A continuous-time quantum walk on a graph $X$ is represented by the complex matrix $\exp (-\mathrm{i} t A)$, where $A$ is the adjacency matrix of $X$ and $t$ is a non-negative time. If the graph models a network of interacting qubits,…

Combinatorics · Mathematics 2018-05-24 Gabriel Coutinho , Chris Godsil

We develop an approach to realize a quantum switch for Rydberg excitation in atoms with $Y$-typed level configuration. We find that the steady population on two different Rydberg states can be reversibly exchanged in a controllable way by…

Atomic Physics · Physics 2017-09-14 Jing Qian

One of the most central and controversial element of quantum mechanics is the use of non zero vectors of a Hilbert space (or, more generally, of one dimension subspaces) for representing the state of a quantum system. In particular, the…

Quantum Physics · Physics 2009-11-13 Olivier Brunet

The phase shift rules enable the estimation of the derivative of a quantum state with respect to phase parameters, providing valuable insights into the behavior and dynamics of quantum systems. This capability is essential in quantum…

Quantum Physics · Physics 2023-09-15 L. A. Markovich , S. Malikis , S. Polla , J. T. Brugués

We consider the quantum dynamical evolution of a fully-connected quantum system subjected to random projective measurements and study the first detection time of an extended subspace of the Hilbert space. Exact analytical expressions are…

Quantum Physics · Physics 2026-01-26 Giuseppe Del Vecchio Del Vecchio , Satya N. Majumdar

We present a general formalism for studying the effects of dynamical heterogeneity in open quantum systems. We develop this formalism in the state space of density operators, on which ensembles of quantum states can be conveniently…

Quantum Physics · Physics 2019-09-04 Amro Dodin , Adam P. Willard

Discrete-time quantum walks are well-known for exhibiting localization, a quantum phenomenon where the walker remains at its initial location with high probability. In companion with a joint Letter, we introduce oscillatory localization,…

Quantum Physics · Physics 2016-12-28 Andris Ambainis , Krišjānis Prūsis , Jevgēnijs Vihrovs , Thomas G. Wong

We present a Hamiltonian that can be used for amplifying the signal from a quantum state, enabling the measurement of a macroscopic observable to determine the state of a single spin. We prove a general mapping between this Hamiltonian and…

Quantum Physics · Physics 2007-05-23 A. Kay

We develop a means of simulating the evolution and measurement of a multipartite quantum state under discrete or continuous evolution using another quantum system with states and operators lying in a real Hilbert space. This extends…

Quantum Physics · Physics 2009-10-26 Matthew McKague , Michele Mosca , Nicolas Gisin

Ichikawa et al. [Phys. Rev. A 78, 052105 (2008)] showed that exchange symmetry gives rise to simple characterization of whether multipartite pure quantum states being either globally entangled or fully separable. In this Brief Report, we…

Quantum Physics · Physics 2010-06-01 Tzu-Chieh Wei