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Quantum networks, which integrate multiple quantum computers and the channels connecting them, are crucial for distributed quantum information processing but remain inherently susceptible to channel noise. Channel purification emerges as a…

Control protocol to drive finite dimensional quantum systems to an arbitrary target state using square pulses is proposed explicitly. It is a multi-cycle control process and in each cycle we apply square pulses to cause single or a few…

Quantum Physics · Physics 2013-12-19 Jianju Tang , H. C. Fu

An asymmetric preparation of the quantum states sent through a noisy channel can enable a new way to monitor and actively compensate the channel noise. The paradigm of such an asymmetric treatment of quantum information is the Bennett 1992…

Quantum Physics · Physics 2015-05-18 Marco Lucamarini , Giovanni Di Giuseppe , David Vitali , Paolo Tombesi

Coherent optical control schemes exploit the coherence of laser pulses to change the phases of interfering dynamical pathways in order to manipulate dynamical processes. These active control methods are closely related to dynamical…

Other Condensed Matter · Physics 2015-05-18 Luis G. C. Rego , L. F. Santos , V. S. Batista

Composite pulses are an efficient tool for robust quantum control. In this work, we derive the form of the composite pulse sequence to implement robust single-qubit gates in a three-level system, where two low-energy levels act as a qubit.…

Quantum Physics · Physics 2021-05-27 Zhi-Cheng Shi , Hai-Ning Wu , Li-Tuo Shen , Yan Xia , X. X. Yi , Shi-Biao Zheng

Faithfully transferring the quantum state is essential for quantum information processing. Here we demonstrate a fast (in 84 ns) and high-fidelity (99.2%) transfer of arbitrary quantum states in a chain of four superconducting qubits with…

Quantum Physics · Physics 2018-11-09 X. Li , Y. Ma , J. Han , Tao Chen , Y. Xu , W. Cai , H. Wang , Y. P. Song , Zheng-Yuan Xue , Zhang-qi Yin , Luyan Sun

A general coherent control scenario to suppress, or accelerate, tunneling of quantum states decaying into a continuum, is investigated. The method is based on deterministic, or stochastic, sequences of unitary pulses that affect the…

Quantum Physics · Physics 2010-09-09 Rajdeep Saha , Victor S. Batista

We propose a protocol for countering the effects of dephasing in quantum state transfer over a noisy spin channel weakly coupled to the sender and receiver qubits. Our protocol, based on performing regular global measurements on the…

Quantum Physics · Physics 2015-10-26 Abolfazl Bayat , Yasser Omar

The aim of dynamical decoupling consists in the suppression of decoherence by appropriate coherent control of a quantum register. Effectively, the interaction with the environment is reduced. In particular, a sequence of $\pi$ pulses is…

Quantum Physics · Physics 2008-08-18 Götz S. Uhrig

A scheme for coherent manipulation of collective atomic states is developed such that total subradiant states, in which spontaneous emission is suppressed into all directions due to destructive interference between neighbor atoms, can be…

Quantum Physics · Physics 2009-11-13 Alexey Kalachev

In order to achieve the high-fidelity quantum control needed for a broad range of quantum information technologies, reducing the effects of noise and system inhomogeneities is an essential task. It is well known that a system can be…

Mesoscale and Nanoscale Physics · Physics 2019-01-30 Junkai Zeng , Xiu-Hao Deng , Antonio Russo , Edwin Barnes

We demonstrate how structured decompositions of unitary operators can be employed to derive control schemes for finite-level quantum systems that require only sequences of simple control pulses such as square wave pulses with finite rise…

Quantum Physics · Physics 2009-11-07 S. G. Schirmer , A. D. Greentree , V. Ramakrishna , H. Rabitz

Dynamical decoupling can be used to preserve arbitrary quantum states despite undesired interactions with the environment, using control Hamiltonians affecting the system only. We present a system-independent analysis of dynamical…

Quantum Physics · Physics 2009-11-13 Kaveh Khodjasteh , Daniel A. Lidar

The presence of decoherence in quantum computers necessitates the suppression of noise. Dynamically corrected gates via specially designed control pulses offer a path forward, but hardware-specific experimental constraints can cause…

Quantum Physics · Physics 2022-05-31 Utkan Güngördü , J. P. Kestner

We present a method that implement directional, perfect state transfers within a branched spin network by exploiting quantum interferences in the time-domain. That provides a tool to isolate subsystems from a large and complex one.…

We study the functional relationship between quantum control pulses in the idealized case and the pulses in the presence of an unwanted drift. We show that a class of artificial neural networks called LSTM is able to model this functional…

Quantum Physics · Physics 2022-08-30 M. Ostaszewski , J. A. Miszczak , P. Sadowski , L. Banchi

Three-level Lambda systems appear in various quantum information processing platforms. In several control schemes, the excited level serves as an auxiliary state for implementing gate operations between the lower qubit states. However,…

Quantum Physics · Physics 2023-08-04 Arian Vezvaee , Evangelia Takou , Paul Hilaire , Matthew F. Doty , Sophia E. Economou

Quantum control aims to manipulate quantum systems toward specific quantum states or desired operations. Designing highly accurate and effective control steps is vitally important to various quantum applications, including energy…

Quantum Physics · Physics 2023-01-11 Xinyu Fei , Lucas T. Brady , Jeffrey Larson , Sven Leyffer , Siqian Shen

We show that a counter-intuitive pulse sequence leads to adiabatic passage between the vibrational levels of three harmonic potentials through parallel dark states in adiabatic approximation. However, the adiabatic assumptions break down…

Chemical Physics · Physics 2007-05-23 Ignacio R. Solá , Vladimir S. Malinovsky

Many realizations of solid-state qubits involve couplings to leakage states lying outside the computational subspace, posing a threat to high-fidelity quantum gate operations. Mitigating leakage errors is especially challenging when the…

Quantum Physics · Physics 2017-07-05 Joydip Ghosh , S. N. Coppersmith , Mark Friesen
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