English
Related papers

Related papers: Witnessing environment dimension through temporal …

200 papers

In reinforcement learning, an agent interacts sequentially with an environment to maximize a reward, receiving only partial, probabilistic feedback. This creates a fundamental exploration-exploitation trade-off: the agent must explore to…

Quantum Physics · Physics 2026-03-27 Josep Lumbreras , Ruo Cheng Huang , Yanglin Hu , Marco Fanizza , Mile Gu

Quantum correlations between measurements of separated observers are crucial for applications like randomness generation and key distribution. Although device-independent security can be certified with minimal assumptions, current protocols…

No quantum system can be considered totally isolated from its environment. In most cases the interaction between the system of interest and the external degrees of freedom deeply changes its dynamics, as described by open quantum system…

In this paper we investigate the robustness of the quantum correlations against the environment effects in various opto-mechanical bipartite systems. For two spatially separated opto-mechanical cavities, we give analytical formula for the…

Quantum Physics · Physics 2015-12-09 J. El Qars , M. Daoud , Ahl Laamara

Continuous-variable Gaussian entanglement is an attractive notion, both as a fundamental concept in quantum information theory, based on the well-established Gaussian formalism for phase-space variables, and as a practical resource in…

Quantum Physics · Physics 2026-05-07 E. Shchukin , P. van Loock

Quantum superposition of high-dimensional states enables both computational speed-up and security in cryptographic protocols. However, the exponential complexity of tomographic processes makes certification of these properties a challenging…

The quantum correlations between a qubit and its environment are described quantitatively in terms of interatomic distance. Specifically, considering a realistic system of two two-level atoms and taking into account the dipole-dipole…

Quantum Physics · Physics 2015-06-05 K. Berrada , F. F. Fanchini , S. Abdel-Khalek

The difficulty to simulate the dynamics of open quantum systems resides in their coupling to many-body reservoirs with exponentially large Hilbert space. Applying a tensor network approach in the time domain, we demonstrate that effective…

Quantum Physics · Physics 2019-05-03 I. A. Luchnikov , S. V. Vintskevich , H. Ouerdane , S. N. Filippov

Periodically-driven systems are ubiquitous in science and technology. In quantum dynamics, even a small number of periodically-driven spins leads to complicated dynamics. Hence, it is of interest to understand what constraints such dynamics…

Quantum Physics · Physics 2022-04-20 Tanmoy Pandit , Alaina M. Green , C. Huerta Alderete , Norbert M. Linke , Raam Uzdin

We demonstrate that quantum incompatibility can always be detected by means of a state discrimination task with partial intermediate information. This is done by showing that only incompatible measurements allow for an efficient use of…

Quantum Physics · Physics 2019-04-09 Claudio Carmeli , Teiko Heinosaari , Alessandro Toigo

Entanglement in multipartite systems is a key resource for quantum information and communication protocols, making its verification in complex systems a necessity. Because an exact calculation of arbitrary entanglement probes is impossible,…

Quantum Physics · Physics 2018-09-18 Stefan Gerke , Werner Vogel , Jan Sperling

We derive a set of algebraic equations, the so-called multipartite separability eigenvalue equations. Based on their solutions, we introduce a universal method for the construction of multipartite entanglement witnesses. We witness…

Quantum Physics · Physics 2015-06-15 J. Sperling , W. Vogel

It is well-known that the violation of a local uncertainty relation can be used as an indicator for the presence of entanglement. Unfortunately, the practical use of these non-linear witnesses has been limited to few special cases in the…

From behavioral sciences to biology to quantum mechanics, one encounters situations where (i) a system outputs several random variables in response to several inputs, (ii) for each of these responses only some of the inputs may "directly"…

Probability · Mathematics 2015-09-01 E. N. Dzhafarov , J. V. Kujala

A symmetric measure of quantum correlation based on the Hilbert-Schmidt distance is presented in this paper. For two-qubit states, we simplify considerably the optimization procedure so that numerical evaluation can be performed…

Quantum Physics · Physics 2011-07-18 Mingjun Shi , Fengjian Jiang , Jiangfeng Du

We consider a new framework where a continuous, though bounded, random variable has unobserved bounds that vary over time. In the context of univariate time series, we look at the bounds as parameters of the distribution of the bounded…

Machine Learning · Statistics 2023-06-26 Amandine Pierrot , Pierre Pinson

A one-dimensional quantum oscillator is monitored by taking repeated position measurements. As a first con- tribution, it is shown that, under a quantum nondemolition measurement scheme applied to a system initially at the ground state, (i)…

Quantum Physics · Physics 2015-11-13 Vincenzo Matta , Vincenzo Pierro

Quantum coherence is one of the primary non-classical features of quantum systems. While protocols such as the Leggett-Garg inequality (LGI) and quantum tomography can be used to test for the existence of quantum coherence and dynamics in a…

Quantum Physics · Physics 2012-12-04 Che-Ming Li , Neill Lambert , Yueh-Nan Chen , Guang-Yin Chen , Franco Nori

We introduce a single-number metric, quantum volume, that can be measured using a concrete protocol on near-term quantum computers of modest size ($n\lesssim 50$), and measure it on several state-of-the-art transmon devices, finding values…

Quantum Physics · Physics 2019-10-14 Andrew W. Cross , Lev S. Bishop , Sarah Sheldon , Paul D. Nation , Jay M. Gambetta

The pseudomode framework provides an exact description of the dynamics of an open quantum system coupled to a non-Markovian environment. Using this framework, the influence of the environment on the system is studied in an equivalent model,…

Quantum Physics · Physics 2024-09-12 Paul Menczel , Ken Funo , Mauro Cirio , Neill Lambert , Franco Nori