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We study quantum phase transitions involving fractional quantum Hall states, using numerical calculations of entanglements and related quantities. We tune finite-size wavefunctions on spherical geometries, by varying the interaction…

Mesoscale and Nanoscale Physics · Physics 2009-06-10 Oleksandr Zozulya , Masudul Haque , Nicolas Regnault

Scrambling unitary dynamics in a quantum system transmutes local quantum information into a non-local web of correlations which manifests itself in a complex spatio-temporal pattern of entanglement. In such a context, we show there can…

Quantum Physics · Physics 2025-06-02 Alan Sherry , Sthitadhi Roy

We study pure phase damping of two qubits due to fluctuating fields. As frequently employed, decoherence is thus described in terms of random unitary (RU) dynamics, i.e., a convex mixture of unitary transformations. Based on a separation of…

Quantum Physics · Physics 2010-12-22 Julius Helm , Walter T. Strunz

We introduce a combination of coherent states as variational test functions for the atomic and radiation sectors to describe a system of Na three- level atoms interacting with a one-mode quantised electromagnetic field, with and without the…

Quantum Physics · Physics 2015-10-22 R. López-Peña , S. Cordero , E. Nahmad-Achar , O. Castaños

Symmetry is a powerful tool for understanding phases of matter in equilibrium. Quantum circuits with measurements have recently emerged as a platform for novel states of matter intrinsically out of equilibrium. Can symmetry be used as an…

Quantum Physics · Physics 2025-06-18 Zhi Li , Zhu-Xi Luo

We present experimentally and numerically accessible quantities that can be used to differentiate among various families of random entangled states. To this end, we analyze the entanglement properties of bipartite reduced states of a…

In this paper we study controllability of a $d$-level atom interacting with the electromagnetic field in a cavity. The system is modelled by an ordered graph $\Gamma$. The vertices of $\Gamma$ describe the energy levels and the edges…

Quantum Physics · Physics 2017-12-21 Thomas Hofmann , Michael Keyl

We explore the role played by the phase in an accurate description of the entanglement of bipartite systems. We first present an appropriate polar decomposition that leads to a truly Hermitian operator for the phase of a single qubit. We…

Quantum Physics · Physics 2007-05-23 Luis L. Sanchez-Soto , Julian Delgado , Andrei B. Klimov , Gunnar Bjork

We show that three-level atoms excited by two cavity modes in a $\Lambda$ configuration close to electromagnetically induced transparency can produce strongly squeezed bright beams or correlated beams which can be used for quantum non…

Quantum Physics · Physics 2009-11-13 Alice Sinatra

We study the ground state properties of the one-dimensional extended Hubbard model at half-filling from the perspective of its particle reduced density matrix. We focus on the reduced density matrix of $2$ fermions and perform an analysis…

Strongly Correlated Electrons · Physics 2022-04-11 Diego L. B. Ferreira , Thiago O. Maciel , Reinaldo O. Vianna , Fernando Iemini

Plasmons are fundamental excitations of metals which can be described in terms of electron dynamics, or in terms of the electromagnetic fields associated with them. In this work we develop a quantum description of plasmons in a double layer…

Mesoscale and Nanoscale Physics · Physics 2023-08-31 Luis Brey , H. A. Fertig

Quantum entanglement, crucial for understanding quantum many-body systems and quantum gravity, is commonly assessed through various measures such as von Neumann entropy, mutual information, and entanglement contour, each with its inherent…

Quantum Physics · Physics 2025-07-08 Liang-Hong Mo , Yao Zhou , Jia-Rui Sun , Peng Ye

We quantitatively analyze the dynamics of the quantum phase distribution associated with the reduced density matrix of a system, as the system evolves under the influence of its environment with an energy-preserving quantum nondemolition…

Quantum Physics · Physics 2009-11-13 Subhashish Banerjee , Joyee Ghosh , R. Ghosh

A new framework is formulated to study entanglement dynamics in many-body quantum systems along with an associated geometric description. In this formulation, called the Quantum Correlation Transfer Function (QCTF), the system's wave…

Quantum Physics · Physics 2025-04-22 Peyman Azodi , Herschel A Rabitz

Passivity is a fundamental concept that constitutes a necessary condition for any quantum system to attain thermodynamic equilibrium, and for a notion of temperature to emerge. While extensive work has been done that exploits this, the…

Quantum Physics · Physics 2021-03-17 Nikolaos Koukoulekidis , Rhea Alexander , Thomas Hebdige , David Jennings

Non-classical states are of practical interest in quantum computing and quantum metrology. These states can be detected through their Wigner function negativity in some regions. In this paper, we calculate the ground state of the…

Quantum Physics · Physics 2021-02-03 Ramón López-Peña , Sergio Cordero , Eduardo Nahmad-Achar , Octavio Castaños

The form of the eigenstates of an atom coupled to a cavity mode displaying a three dimensional periodic profile are obtained. It is shown that the quantized motion leads to degenerate states where the atomic degrees of freedom are masked,…

Quantum Physics · Physics 2020-02-19 R. Gutiérrez-Jáuregui

The entanglement, purity and energy of two isolated two-level atoms which are initially prepared in Bell state and each interacts with a thermal cavity field are investigated by considering the atomic motion and the field-mode structure. We…

Quantum Physics · Physics 2010-05-21 L. Tan , Y. Q. Zhang , Z. H. Zhu , L. W. Liu

In the context of characterizing the structure of quantum entanglement in many-body systems, we introduce the entanglement contour, a tool to identify which real-space degrees of freedom contribute, and how much, to the entanglement of a…

Strongly Correlated Electrons · Physics 2016-11-25 Yangang Chen , Guifre Vidal

Two-level atoms interacting with a one mode cavity field at zero temperature have order parameters which reflect the presence of a quantum phase transition at a critical value of the atom-cavity coupling strength. Two popular examples are…

Quantum Physics · Physics 2015-06-11 J. G. Hirsch , O. Castaños , E. Nahmad-Achar , R. López-Penã