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Although many quantum channels satisfy Completely Positive Trace Preserving (CPTP) condition, there are valid quantum channels that can be non-completely positive (NCP). As memory effects can provide advantages in the dynamics of noisy…

Quantum Physics · Physics 2026-02-18 Anumita Mukhopadhyay , Praggnyamita Ghosh , Shibdas Roy

We consider a model for a quantum battery consisting of a collection of $N$ two-level atoms driven by a classical field and decaying to a common reservoir. In the extensive regime, where the energy $E$ scales as $N$ and the fluctuations…

Quantum Physics · Physics 2024-12-17 Sagar Pokhrel , Julio Gea-Banacloche

Quantum batteries have significant potential applications for future industry and daily life. The capacity is an important indicator for a battery. Methods to improve the capacity of quantum batteries are important. We consider quantum…

Quantum Physics · Physics 2024-05-07 Tinggui Zhang , Hong Yang , Shao-Ming Fei

Efficiency of quantum transport through aggregates with multiple end-points or traps proves to be an emergent and a highly non-equilibrium phenomenon. We present a numerically exact approach for computing the emergent time scale and amount…

Quantum Physics · Physics 2025-09-19 Devansh Sharma , Amartya Bose

Entangling and disentangling capacities are the key manifestation of the nonlocal content of a quantum operation. A lot of effort has been put recently into investigating (dis)entangling capacities of unitary operations, but very little is…

Quantum Physics · Physics 2007-05-23 Berry Groisman

We propose an optimal entanglement concentration protocol (ECP) for nonlocal N-electron systems in a partially entangled pure state, resorting to charge detection and the projection measurement on an additional electron. For each nonlocal…

Quantum Physics · Physics 2014-03-25 Bao-Cang Ren , Tie-Jun Wang , Ming Hua , Fu-Fu Du , Fu-Guo Deng

Accurately determining the coupling strength between polaron states is essential to describe charge-hopping transport in materials. In this work, we revisit methodologies to extract coupling strengths using ab initio approaches. Our…

Materials Science · Physics 2025-03-18 Hala Houmsi , Benoit Sklénard , Marc Guillaumont , François Triozon , Jing Li

Quantum hardware increasingly relies on energy reserves that can later be converted into useful work; yet, most battery-like proposals demand coherent drives or engineered non-equilibrium resources, limiting practicality in noisy settings.…

Quantum states picked from non-trivial symmetry protected topological (SPT) phases have computational power in measurement based quantum computation. This power is uniform across SPT phases, and is unlocked by measurements that break the…

Quantum Physics · Physics 2025-03-27 Arnab Adhikary , Wang Yang , Robert Raussendorf

In recent years, dynamical quantum phase transitions (DQPTs) have emerged as a useful theoretical concept to characterize nonequilibrium states of quantum matter. DQPTs are marked by singular behavior in an \textit{effective free energy}…

Quantum Gases · Physics 2021-09-17 Jad C. Halimeh , Daniele Trapin , Maarten Van Damme , Markus Heyl

We study stochastic thermodynamics for a quantum system of interest whose dynamics are described by a completely positive trace-preserving (CPTP) map as a result of its interaction with a thermal bath. We define CPTP maps with equilibrium…

Quantum Physics · Physics 2017-11-15 Felipe Barra , Cristóbal Lledó

We consider a quantum battery modeled as a set of N independent two-level quantum systems driven by a time dependent classical source. Different figures of merit, such as stored energy, time of charging and energy quantum fluctuations…

Mesoscale and Nanoscale Physics · Physics 2020-07-02 A. Crescente , M. Carrega , M. Sassetti , D. Ferraro

We introduce local filters as a means to detect the entanglement of bound entangled states which do not yield to detection by witnesses based on positive (P) maps which are not completely positive (CP). We demonstrate how such…

Quantum Physics · Physics 2017-09-13 Debmalya Das , Ritabrata Sengupta , Arvind

We consider reversible work extraction from identical quantum batteries. From an ensemble of individually passive states, work can be produced only via global unitary (and thus entangling) operations. However, we show here that there always…

Quantum Physics · Physics 2013-12-16 Karen V. Hovhannisyan , Martí Perarnau-Llobet , Marcus Huber , Antonio Acín

We investigate the connection between quantum resources and extractable work in quantum batteries. We demonstrate that quantum coherence in the battery or the battery-charger entanglement is a necessary resource for generating nonzero…

Quantum Physics · Physics 2022-09-26 Hai-Long Shi , Shu Ding , Qing-Kun Wan , Xiao-Hui Wang , Wen-Li Yang

We present an analysis of the availability and maximum extractable work of quantum batteries in the presence of charge and/or heat steady-state currents. Quantum batteries are modelled as non-interacting open quantum systems (mesoscopic…

Quantum Physics · Physics 2024-10-31 F. H. Kamin , Z. Abuali , H. Ness , S. Salimi

The local Hamiltonian problem consists of estimating the ground-state energy (given by the minimum eigenvalue) of a local quantum Hamiltonian. First, we show the existence of a good product-state approximation for the ground-state energy of…

Quantum Physics · Physics 2016-02-04 Fernando G. S. L. Brandão , Aram W. Harrow

We propose a design of a quantum battery exploiting the non-Hermitian Hamiltonian as a charger. In particular, starting with the ground or the thermal state of the interacting (non-interacting) Hamiltonian as the battery, the charging of…

Quantum Physics · Physics 2024-07-25 Tanoy Kanti Konar , Leela Ganesh Chandra Lakkaraju , Aditi Sen De

Maps that are not completely positive (CP) are often useful to describe the dynamics of open systems. An apparent violation of complete positivity can occur because there are prior correlations of the principal system with the environment,…

Quantum Physics · Physics 2008-04-21 Hilary Carteret , Daniel R. Terno , Karol Zyczkowski

Quantum entanglement, after playing a significant role in the development of the foundations of quantum mechanics, has been recently rediscovered as a new physical resource with potential commercial applications such as, for example,…

Quantum Physics · Physics 2009-11-07 Pawel Horodecki , Artur Ekert