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Related papers: Time-Reversal Symmetry in RDMFT and pCCD with Comp…

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The variational calculation of the two-electron reduced density matrix (2-RDM) is extended to periodic molecular systems. If the 2-RDM theory is extended to the periodic case without consideration of time-reversal symmetry, however, it can…

Chemical Physics · Physics 2016-06-21 Nicholas C. Rubin , David A. Mazziotti

In the nonrelativistic Schr\"{o}dinger equation, the total spin $S$ and spin projection $M$ are good quantum numbers. In contrast, spin symmetry is lost in the presence of spin-dependent interactions such as spin-orbit couplings in…

Chemical Physics · Physics 2023-02-08 Zhendong Li

Driven-dissipative quantum systems generically do not satisfy simple notions of detailed balance based on the time symmetry of correlation functions. We show that such systems can nonetheless exhibit a hidden time-reversal symmetry which…

Quantum Physics · Physics 2021-06-16 David Roberts , Andrew Lingenfelter , Aashish Clerk

The dipole moment is a crucial molecular property linked to a molecular system's bond polarity and overall electronic structure. To that end, the electronic dipole moment, which results from the electron density of a system, is often used…

When treating interactions in quantum dots within a RPA-like approach, time-reversal symmetry plays an important role as higher-order terms -- the Cooper series -- need to be included when this symmetry is present. Here we consider model…

Mesoscale and Nanoscale Physics · Physics 2007-05-23 Denis Ullmo , Hong Jiang , Weitao Yang , Harold U. Baranger

As a new approach to efficiently describe correlation effects in the relativistic quantum world we propose to consider reduced density matrix functional theory, where the key quantity is the first-order reduced density matrix (1-RDM). In…

Chemical Physics · Physics 2022-05-05 M. Rodríguez-Mayorga , K. J. H. Giesbertz , L. Visscher

Calculating the long term solution of ordinary differential equations, such as those of the $N$-body problem, is central to understanding a wide range of dynamics in astrophysics, from galaxy formation to planetary chaos. Because generally…

Instrumentation and Methods for Astrophysics · Physics 2018-01-23 David M. Hernandez , Edmund Bertschinger

One of the fundamental challenges associated with reinforcement learning (RL) is that collecting sufficient data can be both time-consuming and expensive. In this paper, we formalize a concept of time reversal symmetry in a Markov decision…

Machine Learning · Computer Science 2023-11-29 Brett Barkley , Amy Zhang , David Fridovich-Keil

Dynamical decoupling (DD) is a technique for preserving the coherence of quantum mechanical states in the presence of a noisy environment. It uses sequences of inversion pulses to suppress the environmental perturbations by periodically…

Quantum Physics · Physics 2012-06-13 Alexandre M. Souza , Gonzalo A. Álvarez , Dieter Suter

Reduced density-matrix functional theory (RDMFT) is a promising alternative approach to the problem of electron correlation. Like standard density functional theory, it contains an unknown exchange-correlation functional, for which several…

Chemical Physics · Physics 2017-03-03 N. N. Lathiotakis , Miguel A. L. Marques

It is proved that when the retarded effect (or multiple moment effect) of radiation fields is taken into account, the high order stimulated radiation and stimulated absorption probabilities of light are not the same so that time reversal…

General Physics · Physics 2008-04-10 Mei Xiaochun

Coherent control of atomic and molecular scattering relies on the preparation of colliding particles in superpositions of internal states, establishing interfering pathways that can be used to tune the outcome of a scattering process.…

Atomic Physics · Physics 2024-12-20 Adrien Devolder , Timur V. Tscherbul , Paul Brumer

We propose a novel scheme to bring reduced density matrix functional theory (RDMFT) into the realm of density functional theory (DFT) that preserves the accurate density functional description at equilibrium, while incorporating accurately…

Chemical Physics · Physics 2014-11-07 Nektarios N. Lathiotakis , Nicole Helbig , Angel Rubio , Nikitas I. Gidopoulos

We investigate the numerical stability of time-dependent coupled-cluster theory for many-electron dynamics in intense laser pulses, comparing two coupled-cluster formulations with full configuration interaction theory. Our numerical…

In order to explore the effects of high levels of electron correlation on the real-time coupled cluster formalism and algorithmic behavior, we introduce a time-dependent implementation of the CC3 singles, doubles and approximate triples…

Chemical Physics · Physics 2025-01-23 Zhe Wang , Håkon Emil Kristiansen , Thomas Bondo Pedersen , T. Daniel Crawford

Quantum effects arising from manifestly broken time-reversal symmetry are investigated using time-dependent perturbation theory in a simple model. The forward time and the backward time Hamiltonians are taken to be different and hence the…

Quantum Physics · Physics 2023-07-10 Rajat Kumar Pradhan

We develop an analytic-gradient based method for relativistic coupled-cluster calculations of effective electric field, $\mathcal{E}_{\text{eff}}$, with improved efficiency and robustness over the previous state of the art. The enhanced…

Atomic Physics · Physics 2021-08-04 Chaoqun Zhang , Xuechen Zheng , Lan Cheng

Real-time time-dependent density functional theory (RT-TDDFT) is a powerful approach for investigating various ultrafast phenomena in materials. However, most existing RT-TDDFT studies rely on adiabatic local or semi-local approximations,…

Materials Science · Physics 2025-12-23 Yuyang Ji , Haotian Zhao , Peize Lin , Xinguo Ren , Lixin He

Reduced density-matrix functional theory (RDMFT) provides a variational route to electronic correlations beyond conventional density-functional approximations, but explicit evaluations of density-matrix functionals still scale exponentially…

Chemical Physics · Physics 2026-05-19 Konstantin Tamoev , Robert Schade , Thomas D. Kühne

Time reversal symmetry occupies a distinctive role in quantum mechanics, fundamentally requiring an anti-unitary operator to ensure a physically consistent representation. As such, the time reversal operator combines a unitary…

General Relativity and Quantum Cosmology · Physics 2026-03-27 Ovidiu Racorean
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