13 research outputs found
Quantum speed limit time for moving qubit inside leaky cavity
The shortest time required for a system to transform from an initial state to
its orthogonal state is known as the quantum speed limit time. Calculating the
QSL time for closed and open systems has been the subject of much recent works.
QSL time is inversely related to the evolution rate of the system. In such a
way that with increasing this time, the speed of evolution decreases and vice
versa. In this work we study the QSL time for moving qubit inside leaky cavity.
It is observed that for both weak coupling and strong coupling regimes the QSL
time increases with increasing the velocity of the qubit inside the leaky
cavity. It is observed that with increasing qubit velocity, the speed of the
evolution tends to a constant value and the system becomes more stable.Comment: 10 pages, 3 figur
Enhancing the efficiency of open quantum batteries via adjusting the classical driving field
In the context of quantum information, a quantum battery refers to a system
composed of quantum particles that can store and release energy in a way that
is governed by the principles of quantum mechanics. The study of open quantum
batteries is motivated by the fact that real-world quantum systems are almost
never perfectly isolated from their environment. One important challenge in the
study of open quantum batteries is to develop theoretical models that
accurately capture the complex interactions between the battery and its
environment. the goal of studying open quantum batteries is to develop
practical methods for building and operating quantum devices that can store and
release energy with high efficiency and reliability, even in the presence of
environmental noise and other sources of decoherence. The charging process of
open quantum batteries under the influence of dissipative environment will be
studied. In this Work, the effect of the classical driving field on the
charging process of open quantum batteries will be investigated. The classical
driving field can be used to manipulate the charging and discharging process of
the battery, leading to enhanced performance and improved efficiency. It also
will be showed that the efficiency of open quantum batteries depends on
detuning between the qubit and the classical driving field and central
frequency of the cavity and the classical driving field.Comment: 9 pages, 11 figures. This is just a draft version of the manuscript.
We welcome your comments and contribution
Practical Scheme for Realization of a Quantum Battery
We propose a practical scheme for a quantum battery consisting of an
atom-cavity interacting system under a structured reservoir in the
non-Markovian regime. We investigate a multi-parameter regime for the
cavity-reservoir coupling and reveal how these parameters affect the
performance of the quantum battery. Our proposed scheme is simple and may be
achievable for practical realization and implementation.Comment: 7 Figures, 8 pages. All comments are welcom
Tripartite quantum-memory-assisted entropic uncertainty relations for multiple measurements
It is possible to extend the bipartite quantum-memory-assisted entropic
uncertainty relation (QMA-EUR) to the tripartite one in which the memory is
split into two parts. The uncertainty relations are usually applied to two
incompatible observables, however, many kinds of research have been made to
generalize the uncertainty relations to more than two observables. Recently,
although many relations have been obtained for bipartite QMA-EUR for multiple
measurements, the case of tripartite remains unstudied. In this work, we obtain
several tripartite QMA-EURs for multiple measurements and show that the lower
bounds of these relations have three terms that depend on the complementarity
of the observables, the conditional von-Neumann entropies, the Holevo
quantities, and the mutual information. Moreover, it is revealed that one of
the terms is related to the strong subadditivity inequality. These uncertainty
relations are expected to be helpful in the foundations of quantum theory and
quantum information processing.Comment: 14pages, 3 figure
Holevo bound of entropic uncertainty relation under Unruh channel in the context of open quantum systems
The uncertainty principle is the most important feature of quantum mechanics, which can be called the heart of quantum mechanics. This principle sets a lower bound on the uncertainties of two incompatible measurement. In quantum information theory, this principle is expressed in terms of entropic measures. Entropic uncertainty bound can be altered by considering a particle as a quantum memory. In this work we investigate the entropic uncertainty relation under the relativistic motion. In relativistic uncertainty game Alice and Bob agree on two observables, and , Bob prepares a particle constructed from the free fermionic mode in the quantum state and sends it to Alice, after sending, Bob begins to move with an acceleration a, then Alice does a measurement on her particle A and announces her choice to Bob, whose task is then to minimize the uncertainty about the measurement outcomes. we will have an inevitable increase in the uncertainty of the Alic’s measurement outcome due to information loss which was stored initially in B. In this work we look at the Unruh effect as a quantum noise and we will characterize it as a quantum channel
Protecting the entropic uncertainty lower bound in Markovian and non-Markovian environment via additional qubits
The uncertainty principle is an important principle in quantum theory. Based on this principle, it is impossible to predict the measurement outcomes of two incompatible observables, simultaneously. The uncertainty principle basically is expressed in terms of the standard deviation of the measured observables. In quantum information theory, it is shown that the uncertainty principle can be expressed by Shannon’s entropy. The entopic uncertainty lower bound can be altered by considering a particle as the quantum memory which is correlated with the measured particle. We assume that the quantum memory is an open system. We also select the quantum memory from N qubit which interact with common reservoir. In this work we investigate the effects of the number of additional qubits in reservoir on entropic uncertainty lower bound. We conclude that the entropic uncertainty lower bound can be protected from decoherence by increasing the number of additional qubit in reservoir