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We study the time evolution of a qubit linearly coupled with a quantum environment under a sequence of short pi pulses. Our attention is focused on the case where qubit-environment interactions induce the decoherence with population decay.…

Quantum Physics · Physics 2015-06-26 Takahiro Murakami , Yositake Takane

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…

The pulse control of decoherence in a qubit interacting with a quantum environment is studied with focus on a general case where decoherence is induced by both pure dephasing and population decay. To observe how the decoherence is…

Quantum Physics · Physics 2009-11-11 Takahiro Murakami , Yositake Takane

Decoherence may significantly affect the polarization state of optical pulses propagating in dispersive media because of the unavoidable presence of more than a single frequency in the envelope of the pulse. Here we report on the…

Microwave pulses are used ubiquitously to control and measure qubits fabricated on superconducting circuits. Due to continual environmental coupling, the qubits undergo decoherence both when it is free and during its interaction with the…

Quantum Physics · Physics 2020-12-10 Yibo Gao , Shijie Jin , Yan Zhang , Hou Ian

We study the suppression of noise-induced phase decoherence in a single atomic qubit by employing pulse sequences. The atomic qubit is composed of a single neutral atom in a far-detuned optical dipole trap and the phase decoherence may…

Quantum Physics · Physics 2015-05-13 Chih-Sung Chuu , Chuanwei Zhang

We explore the physical limits of pulsed dynamical decoupling methods for decoherence control as determined by finite timing resources. By focusing on a decohering qubit controlled by arbitrary sequences of $\pi$-pulses, we establish a…

Quantum Physics · Physics 2011-04-11 Kaveh Khodjasteh , Tamás Erdélyi , Lorenza Viola

A method is proposed for obtaining the spectrum for noise that causes the phase decoherence of a qubit directly from experimentally available data. The method is based on a simple relationship between the spectrum and the coherence time of…

Quantum Physics · Physics 2015-05-28 Tatsuro Yuge , Susumu Sasaki , Yoshiro Hirayama

We investigate the effectiveness of different dynamical decoupling protocols for storage of a single qubit in the presence of a purely dephasing bosonic bath, with emphasis on comparing quantum coherence preservation under uniform vs.…

Quantum Physics · Physics 2015-05-14 Thomas E. Hodgson , Lorenza Viola , Irene D'Amico

We present a new strategy for multipulse control over decoherence. When a two-level system interacts with a reservoir characterized by a specific frequency, we find that the decoherence is effectively suppressed by synchronizing the…

Quantum Physics · Physics 2009-11-10 Chikako Uchiyama , Masaki Aihara

Many solid-state qubit systems are afflicted by low frequency noise mechanisms that operate along two perpendicular axes of the Bloch sphere. Depending on the qubit's control fields, either noise can be longitudinal or transverse to the…

Quantum Physics · Physics 2022-02-02 Guy Ramon , Łukasz Cywiński

The effect of a number of mechanisms designed to suppress decoherence in open quantum systems are studied with respect to their effectiveness at slowing down the loss of entanglement. The effect of photonic band-gap materials and frequency…

Quantum Physics · Physics 2013-07-09 Sandeep K Goyal , Subhashish Banerjee , Sibasish Ghosh

We analytically and numerically study the effects of pulsed control on the decoherence of a qubit coupled to a quantum spin bath. When the environment is critical, decoherence is faster and we show that the control is relatively more…

The dynamics of a decohering two-level system driven by a suitable control Hamiltonian is studied. The control procedure is implemented as a sequence of radiofrequency pulses that repetitively flip the state of the system, a technique that…

Quantum Physics · Physics 2009-10-31 Lorenza Viola , Seth Lloyd

We explore a strategy for protecting the evolution of a qubit against the effects of environmental noise based on the application of controlled time-dependent perturbations. In the case of a purely decohering coupling, an explicit sequence…

Quantum Physics · Physics 2007-05-23 Lorenza Viola , Seth Lloyd

In this work, two experimentally feasible methods of decoherence engineering-one based on the application of stochastic classical kicks and the other based on temporally randomized pulse sequences are combined. A different coupling…

Quantum Physics · Physics 2016-02-10 Govind Unnikrishnan

In this study, a circuitry model of the coupling of a qubit to reservoir modes is defined to clearly determine the effect of the reservoir modes on the qubit decay and dephasing rates. The main goal is to theoretically calculate the…

Quantum Physics · Physics 2022-05-27 Ahmad Salmanogli

Different approaches in quantifying environmentally-induced decoherence are considered. We identify a measure of decoherence, derived from the density matrix of the system of interest, that quantifies the environmentally induced error,…

Mesoscale and Nanoscale Physics · Physics 2010-10-12 Arkady Fedorov , Leonid Fedichkin , Vladimir Privman

We study the phonon-induced dephasing of the exciton state in a quantum dot excited by a sequence of ultra-short pulses. We show that the multiple-pulse control leads to a considerable improvement of the coherence of the optically excited…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 V. M. Axt , P. Machnikowski , T. Kuhn

We investigate the usefulness and viability of the scheme developed by Viola and Lloyd [Phys. Rev. A 58, 2733 (1998)] to control dephasing in the context of exciton-based quantum computation with self-assembled quantum dots. We demonstrate…

Mesoscale and Nanoscale Physics · Physics 2008-03-31 Thomas E. Hodgson , Lorenza Viola , Irene D'Amico
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