English
Related papers

Related papers: Operator relationship between conventional coupled…

200 papers

The nonperturbative Hamiltonian eigenvalue problem for bound states of a quantum field theory is formulated in terms of Dirac's light-front coordinates and then approximated by the exponential-operator technique of the many-body…

High Energy Physics - Phenomenology · Physics 2015-06-11 J. R. Hiller

We attempt the use of a unitary operator to approximate the lattice Boltzmann collision operator. We use a modified amplitude encoding to bypass the renormalization that would have required classical processing at every step (thus eroding…

Quantum Physics · Physics 2026-01-08 Wael Itani , Katepalli R. Sreenivasan

We demonstrate how structured decompositions of unitary operators can be employed to derive control schemes for finite-level quantum systems that require only sequences of simple control pulses such as square wave pulses with finite rise…

Quantum Physics · Physics 2009-11-07 S. G. Schirmer , A. D. Greentree , V. Ramakrishna , H. Rabitz

General formulas of the two-electron operator representing either atomic or effective interactions are given in a coupled tensorial form in relativistic approximation. The alternatives of using uncoupled, coupled and antisymmetric…

Atomic Physics · Physics 2010-04-30 Rytis Jursenas , Gintaras Merkelis

The contributions to the coefficient functions of the quark and the mixed quark-gluon condensate to mesonic correlators are calculated for the first time to all orders in the quark masses, and to lowest order in the strong coupling…

High Energy Physics - Phenomenology · Physics 2009-10-22 M. Jamin , M. Muenz

Quantum simulation is a promising application of future quantum computers. Product formulas, or Trotterization, are the oldest and still remain an appealing method to simulate quantum systems. For an accurate product formula approximation,…

Quantum Physics · Physics 2024-11-04 Chi-Fang , Chen , Fernando G. S. L. Brandão

We study methods to replace entangling operations with random local operations in a quantum computation, at the cost of increasing the number of required executions. First, we consider "space-like cuts" where an entangling unitary is…

Quantum Physics · Physics 2025-01-23 Aram W. Harrow , Angus Lowe

Achieving an accurate description of fermionic systems typically requires considerably many more orbitals than fermions. Previous resource analyses of quantum chemistry simulation often failed to exploit this low fermionic number…

Quantum Physics · Physics 2022-05-24 Sam McArdle , Earl Campbell , Yuan Su

The existing notion of the shared entangled state-assisted remote preparation of unitary operator (equivalently the existing notion of quantum remote control) using local operation and classical communication is generalized to a scenario…

Quantum Physics · Physics 2024-03-14 Satish Kumar , Nguyen Ba An , Anirban Pathak

The nonperturbative Hamiltonian eigenvalue problem for bound states of a quantum field theory is formulated in terms of Dirac's light-front coordinates and then approximated by the exponential-operator technique of the many-body…

High Energy Physics - Phenomenology · Physics 2015-06-11 J. R. Hiller

Coupled cluster theory is the method of choice for weakly correlated systems. But in the strongly correlated regime, it faces a symmetry dilemma, where it either completely fails to describe the system, or has to artificially break certain…

Chemical Physics · Physics 2020-05-14 Yiheng Qiu , Thomas M. Henderson , Jinmo Zhao , Gustavo E. Scuseria

We consider the sampling of the coupled cluster expansion within stochastic coupled cluster theory. Observing the limitations of previous approaches due to the inherently non-linear behaviour of a coupled cluster wavefunction representation…

Chemical Physics · Physics 2018-08-14 Charles J. C. Scott , Alex J. W. Thom

We investigate the rational approximation of fractional powers of unbounded positive operators attainable with a specific integral representation of the operator function. We provide accurate error bounds by exploiting classical results in…

Numerical Analysis · Mathematics 2024-03-19 Lidia Aceto , Paolo Novati

In this article, we compare the methods implementing the real-time evolution operator generated by a unitary diagonal matrix where its entries obey a known underlying real function. When the size of the unitary diagonal matrix is small, a…

Quantum Physics · Physics 2025-03-18 Xinchi Huang , Taichi Kosugi , Hirofumi Nishi , Yu-ichiro Matsushita

We study factorizations of operator valued functions of weighted Schur classes over multiply-connected domains. There is a correspondence between functions from weighted Schur classes and so-called ``conservative curved'' systems introduced…

Functional Analysis · Mathematics 2007-05-23 Alexey Tikhonov

Quantum physics has revealed many interesting formal properties associated with the algebra of two operators, A and B, satisfying the partial commutation relation AB-BA=1. This study surveys the relationships between classical combinatorial…

Combinatorics · Mathematics 2015-03-17 Pawel Blasiak , Philippe Flajolet

We derive formulas which connect cumulants of particle numbers observed with efficiency losses with the original ones based on the binomial model. These formulas can describe the case with multiple efficiencies in a compact form. Compared…

Nuclear Theory · Physics 2016-04-27 Masakiyo Kitazawa

Many quantum algorithms have daunting resource requirements when compared to what is available today. To address this discrepancy, a quantum-classical hybrid optimization scheme known as "the quantum variational eigensolver" was developed…

Quantum Physics · Physics 2016-02-05 Jarrod R. McClean , Jonathan Romero , Ryan Babbush , Alán Aspuru-Guzik

A full coupled-cluster expansion suitable for sparse algebraic operations is developed by expanding the commutators of the Baker-Campbell-Hausdorff series explicitly for cluster operators in binary representations. A full coupled-cluster…

Chemical Physics · Physics 2018-09-13 Enhua Xu , Motoyuki Uejima , Seiichiro L. Ten-no

A well-known theorem factors a scalar coefficient differential operator given a linearly independent set of functions in its kernel. The goal of this paper is to generalize this useful result to other types of operators. In place of the…

Rings and Algebras · Mathematics 2015-11-26 Alex Kasman