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Inspired by holographic Wilsonian renormalization, we consider coarse graining a quantum system divided between short distance and long distance degrees of freedom, coupled via the Hamiltonian. Observations using purely long distance…

High Energy Physics - Theory · Physics 2018-08-01 Cesar Agon , Vijay Balasubramanian , Skyler Kasko , Albion Lawrence

The method of the envelope Hamiltonian [K. Toyota, U. Saalmann, and J. M. Rost, New J. Phys. {\bf 17}, 073005~(2015)] is applied to further study a detachment dynamics of a model negative ion in one-dimension in high-frequency regime. This…

Atomic Physics · Physics 2016-10-19 Koudai Toyota

We propose a general-purpose, self-adaptive approach to construct variational wavefunction ans\"atze for highly accurate quantum dynamics simulations based on McLachlan's variational principle. The key idea is to dynamically expand the…

Variational quantum algorithms offer a promising framework for solving eigenvalue problems on near-term quantum hardware, yet their applicability beyond electronic structure calculations remains relatively unexplored. In this work, we…

Materials Science · Physics 2026-04-21 Naman Khandelwal , Bikash K. Behera , Ashok Kumar , Prasanta K. Panigrahi

The physical model of a nonrelativistic quantized Schrodinger's electron (SE) is offered. The behaviour of the SE well spread elementary electric charge had been understood by means of two independent and different in a frequency and size…

Quantum Physics · Physics 2007-05-23 Josiph Mladenov Rangelov

We describe a wave-mechanical implementation of classically chaotic n-disk scattering based on thin 2-D microwave cavities. Two, three, and four-disk scattering are investigated in detail. The experiments, which are able to probe the…

Condensed Matter · Physics 2009-10-31 Wentao Lu , Lorenza Viola , Kristi Pance , Michael Rose , S. Sridhar

We develop a class of C1-continuous time integration methods that are applicable to conservative problems in elastodynamics. These methods are based on Hamilton's law of varying action. From the action of the continuous system we derive a…

Numerical Analysis · Mathematics 2016-04-18 Janine C. Mergel , Roger A. Sauer , Sina Ober-Blöbaum

We expand the quantum mechanical wavefunction in a complete set of square integrable orthonormal basis such that the matrix representation of the Hamiltonian operator is tridiagonal and symmetric. Consequently, the matrix wave equation…

Mathematical Physics · Physics 2018-03-02 A. D. Alhaidari

Simulating the dynamics of a nonequilibrium quantum many-body system by computing the two-time Green's function associated with such a system is computationally challenging. However, we are often interested in the time diagonal of such a…

Statistical Mechanics · Physics 2021-07-21 Jia Yin , Yang-hao Chan , Felipe da Jornada , Diana Qiu , Chao Yang , Steven G. Louie

Hybrid quantum-classical algorithms have been proposed to circumvent noise limitations in quantum computers. Such algorithms delegate only a calculation of the expectation value to the quantum computer. Among them, the Variational Quantum…

Strongly Correlated Electrons · Physics 2022-11-02 Baptiste Anselme Martin , Pascal Simon , Marko J. Rančić

Variational algorithms are promising candidates to be implemented on near-term quantum computers. The variational quantum eigensolver (VQE) is a prominent example, where a parametrized trial state of the quantum mechanical wave function is…

We propose a general variational fermionic many-body wavefunction that generates an effective Hamiltonian in a quadratic form, which can then be exactly solved. The theory can be constructed within the density functional theory framework,…

Strongly Correlated Electrons · Physics 2020-10-30 Xindong Wang , Xiao Chen , Liqin Ke , Hai-Ping Cheng , B. N. Harmon

A novel data-driven method of modal analysis for complex flow dynamics, termed as reduced-order variational mode decomposition (RVMD), has been proposed, combining the idea of the separation of variables and a state-of-the-art nonstationary…

Fluid Dynamics · Physics 2022-09-27 Zi-Mo Liao , Zhiye Zhao , Liang-Bing Chen , Zhen-Hua Wan , Nan-Sheng Liu , Xi-Yun Lu

Evaluating the entanglement spectrum is essential for characterizing exotic quantum phases such as quantum criticality and topological order. However, for large quantum many-body systems, this task is hindered by the exponential measurement…

Quantum Physics · Physics 2026-05-12 Shohei Miyakoshi , Takanori Sugimoto , Tomonori Shirakawa , Seiji Yunoki , Hiroshi Ueda

By exploiting the invariance of the molecular Hamiltonian by a unitary transformation of the orbitals it is possible to significantly shorter the depth of the variational circuit in the Variational Quantum Eigensolver (VQE) algorithm by…

Quantum Physics · Physics 2025-09-03 Leonardo Ratini , Chiara Capecci , Leonardo Guidoni

The variational quantum eigensolver (or VQE) uses the variational principle to compute the ground state energy of a Hamiltonian, a problem that is central to quantum chemistry and condensed matter physics. Conventional computing methods are…

We formulate a finite-temperature scheme of the variational cluster approximation (VCA) particularly suitable for an exact-diagonalization cluster solver. Based on the analytical properties of the single-particle Green's function matrices,…

Strongly Correlated Electrons · Physics 2018-11-09 Kazuhiro Seki , Tomonori Shirakawa , Seiji Yunoki

A novel method based on spectral Green functions is presented for the simulation of driven open quantum dynamics that can be described by the Lindblad master equation in Liouville density operator space. The method extends the Hilbert space…

Quantum Physics · Physics 2021-02-03 Alexander Karabanov , Walter Köckenberger

A new method for calculation of band structure has been proposed based on the Green's function theory and local sampling. Potential energy in the Hamiltonian of Schrodinger's equation is approximated with a series of sampled Dirac delta…

Mesoscale and Nanoscale Physics · Physics 2010-02-24 Milad Khoshnegar , Sina Khorasani , Amirhossein Hosseinnia

Theoretical descriptions of non equilibrium dynamics of quantum many-body systems essentially employ either (i) explicit treatments, relying on truncation of the expansion of the many-body wave function, (ii) compressed representations of…