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Quantum computation in solid state quantum dots faces two significant challenges: Decoherence from interactions with the environment and the difficulty of generating local magnetic fields for the single qubit rotations. This paper presents…

Quantum Physics · Physics 2007-05-23 C. Stephen Hellberg

We consider interactions that generate a universal set of quantum gates on logical qubits encoded in a collective-dephasing-free subspace, and discuss their implementations with trapped ions. This allows for the removal of the by-far…

Quantum Physics · Physics 2016-08-14 Leandro Aolita , Luiz Davidovich , Kihwan Kim , Hartmut Häffner

We propose and analyse a robust quantum state transfer protocol by the use of a combination of coherent quantum coupling and decoherence-free subspaces in a coupled quantum spin chain. Under decoherence, an arbitrary unknown quantum state…

Quantum Physics · Physics 2015-04-08 Wei Qin , Chuan Wang , Xiangdong Zhang

Coherent interaction of a quantum system with environment usually induces quantum decoherence. However, remarkably, in certain configurations the coherent system-environment coupling can be simultaneously explored to engineer a specific…

Quantum coherences are paramount resources for applications, such as quantum-enhanced light-harvesting or quantum computing, which are fragile against environmental noise. We here derive generalized quantum master equations using…

Quantum Physics · Physics 2020-09-03 Chahan M. Kropf

In this work we investigate the relation between quantum measurements and decoherence, in order to formally express the necessity of the latter for obtaining an informative output from the former. To this aim, referring to the Von Neumann…

Quantum Physics · Physics 2015-06-23 Pietro Liuzzo-Scorpo , Alessandro Cuccoli , Paola Verrucchi

Preserving the precision of the parameter of interest in the presence of environmental decoherence is an important yet challenging task in dissipative quantum sensing. In this work, we study quantum metrology when the decoherence effect is…

Quantum Physics · Physics 2024-11-05 Jing Yang

Decoherence of a quantum system (which then starts to display classical features) results from the interaction of the system with the environment, and is well described in the framework of the theory of continuous quantum measurements…

Quantum Physics · Physics 2010-12-17 Michael B. Mensky

We present a scheme to implement a universal set of quantum gates based on achievable interactions, and the gates can be protected against decoherences through dynamical-decoupling approach without encoding. By properly designing system…

Quantum Physics · Physics 2022-09-08 Chunfeng Wu , Chunfang Sun , Jing-Ling Chen , X. X. Yi

We demonstrate by an explicit model calculation that the decay of entanglement of two two-state systems (two qubits) is governed by the product of the factors that measure the degree of decoherence of each of the qubits, subject to…

Quantum Physics · Physics 2010-10-12 D. Tolkunov , V. Privman , P. K. Aravind

A scheme is proposed for protecting quantum states from both independent decoherence and cooperative decoherence. The scheme operates by pairing each qubit (two-state quantum system) with an ancilla qubit and by encoding the states of the…

Quantum Physics · Physics 2009-01-23 Lu-Ming Duan , Guang-Can Guo

Real quantum systems couple to their environment and lose their intrinsic quantum nature through the process known as decoherence. Here we present a method for minimizing decoherence by making it energetically unfavorable. We present a…

Quantum Physics · Physics 2009-11-06 D. Bacon , K. R. Brown , K. B. Whaley

In the lectures we will be concerned with some aspects of physical implementations of quantum gate operations which are necessary for quantum information processing. We will discuss two possible realizations. One of them is based on qubits…

Quantum Physics · Physics 2007-05-23 Stefan Scheel , Jiannis Pachos , E. A. Hinds , Peter L. Knight

It is known that a quantum system with finite degrees of freedom can simulate a composite of a system and an environment if the state of the hypothetical environment is randomized by external manipulation. We show theoretically that any…

Decoherence is the fundamental obstacle limiting the performance of quantum information processing devices. The problem of transmitting a quantum state (known or unknown) from one place to another is of great interest in this context. In…

Quantum Physics · Physics 2023-01-12 Maxim A. Gavreev , Evgeniy O. Kiktenko , Alena S. Mastiukova , Aleksey K. Fedorov

The stabilizing properties of one-error correcting jump codes are explored under realistic non-ideal conditions. For this purpose the quantum algorithm of the tent-map is decomposed into a universal set of Hamiltonian quantum gates which…

Quantum Physics · Physics 2007-05-23 Oliver Kern , Gernot Alber

Measurement based quantum computation (MBQC) is an effective paradigm for universal quantum computation. In this scheme, the universal set of quantum gates are realized by only local measurements on the prior prepared cluster states. The…

Quantum Physics · Physics 2013-11-26 Ding Zhong , Jian Wang , Ning Dai , Liang-Zhu Mu , Heng Fan

Decoherence-Free Subsystems (DFS) are a powerful means of protecting quantum information against noise with known symmetry properties. Although Hamiltonians theoretically exist that can implement a universal set of logic gates on DFS…

Quantum Physics · Physics 2007-05-23 P. Cappellaro , J. S. Hodges , T. F. Havel , D. G. Cory

Quantum properties of the probes used to estimate a classical parameter can be used to attain accuracies that beat the standard quantum limit. When qubits are used to construct a quantum probe, it is known that initializing $n$ qubits in an…

Quantum Physics · Physics 2009-11-13 Anil Shaji , Carlton M. Caves

In this paper, we propose a method to probe entanglement in a theoretically inaccessible quantum system with either a discrete or continuous basis. Our approach leverages insights into the entanglement distribution within a four-partite…

Quantum Physics · Physics 2025-07-10 Pablo C. López Vázquez , Luis M. Piñuelas , Gustavo Montes