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The formation of coplanar spin spirals is a common motif in the magnetic ordering of many frustrated magnets. For classical antiferromagnets, geometric frustration can lead to a massively degenerate ground state manifold of spirals whose…

Strongly Correlated Electrons · Physics 2017-08-31 Jan Attig , Simon Trebst

Interacting fermions on a lattice can develop strong quantum correlations, which lie at the heart of the classical intractability of many exotic phases of matter. Seminal efforts are underway in the control of artificial quantum systems,…

Mesoscale and Nanoscale Physics · Physics 2017-08-16 T. Hensgens , T. Fujita , L. Janssen , Xiao Li , C. J. Van Diepen , C. Reichl , W. Wegscheider , S. Das Sarma , L. M. K. Vandersypen

We compute the zero bias conductance of electrons through a single ballistic channel weakly coupled to a side quantum dot with Coulomb interaction. In contrast to the standard setup which is designed to measure the transport through the…

Mesoscale and Nanoscale Physics · Physics 2015-06-24 M. E. Torio , K. Hallberg , S. Flach , A. E. Miroshnichenko , M. Titov

A mapping is obtained relating radial screened Coulomb systems with low screening parameters to radial anharmonic oscillators in N-dimensional space. Using the formalism of supersymmetric quantum mechanics, it is shown that exact solutions…

Quantum Physics · Physics 2007-05-23 Bulent Gonul , Okan Ozer , Mehmet Kocak

Constraints make hard optimization problems even harder to solve on quantum devices because they are implemented with large energy penalties and additional qubit overhead. The parity mapping, which has been introduced as an alternative to…

Quantum Physics · Physics 2023-03-20 Maike Drieb-Schön , Kilian Ender , Younes Javanmard , Wolfgang Lechner

Quantum simulation is a promising near term application for mesoscale quantum information processors, with the potential to solve computationally intractable problems at the scale of just a few dozen interacting quantum systems. Recent…

Quantum Physics · Physics 2014-08-14 David L. Hayes , Steven T. Flammia , Michael J. Biercuk

We construct and analyze a two-dimensional frustrated quantum spin model with plaquette order, in which the low-energy dynamics is controlled by spin singlets. At a critical value of frustration the singlet spectrum becomes gapless,…

Strongly Correlated Electrons · Physics 2016-08-31 Valeri N. Kotov , Michael E. Zhitomirsky , Oleg P. Sushkov

This article provides an introduction to the ideas behind the multilevel blocking (MLB) approach to the fermion sign problem in path-integral Monte Carlo simulations, and also gives a detailed discussion of MLB results for quantum dots. MLB…

Strongly Correlated Electrons · Physics 2016-11-23 R. Egger , C. H. Mak

Magnetic frustrations in two-dimensional materials provide a rich playground to engineer unconventional phenomena such as non-collinear magnetic order and quantum spin-liquid behavior. However, despite intense efforts, a realization of…

Strongly Correlated Electrons · Physics 2022-10-18 Guangze Chen , Malte Rösner , Jose L. Lado

The many-body theory of interacting electrons poses an intrinsically difficult problem that requires simplifying assumptions. For the determination of electronic screening properties of the Coulomb interaction, the Random Phase…

Strongly Correlated Electrons · Physics 2021-07-26 Erik G. C. P. van Loon , Malte Rösner , Mikhail I. Katsnelson , Tim O. Wehling

It has been a long sought goal of Quantum Simulation to find answers to long standing questions in condensed matter physics. A famous example is the ground and the excitations of 2D Hubbard model with strong repulsion below half filling.…

Quantum Gases · Physics 2020-03-09 Tin-Lun Ho

The fermion sign problem remains the primary obstacle in simulating the thermodynamic properties of various fermionic systems. In this work, we present a sign-blocking method to mitigate the numerical instability inherent in the sign…

Computational Physics · Physics 2026-04-14 Yunuo Xiong , Hongwei Xiong

Numerical simulations of strongly correlated electron systems suffer from the notorious fermion sign problem which has prevented progress in understanding if systems like the Hubbard model display high-temperature superconductivity. Here we…

Strongly Correlated Electrons · Physics 2015-06-24 S. Chandrasekharan , J. Cox , J. C. Osborn , U. -J. Wiese

The Coulomb gap observed in tunneling between parallel two-dimensional electron systems, each at half filling of the lowest Landau level, is found to depend sensitively on the presence of an in-plane magnetic field. Especially at low…

Mesoscale and Nanoscale Physics · Physics 2016-09-14 J. P. Eisenstein , T. Khaire , D. Nandi , A. D. K. Finck , L. N. Pfeiffer , K. W. West

We propose a scheme to realize a frustrated Bose-Hubbard model with ultracold atoms in an optical lattice that comprises the frustrated spin-1/2 quantum XX model. Our approach is based on a square ladder of magnetic flux close to $\pi$ with…

Quantum Gases · Physics 2023-11-01 Luca Barbiero , Josep Cabedo , Maciej Lewenstein , Leticia Tarruell , Alessio Celi

Superconductivity in a partially filled flat band presents a vexing conceptual hurdle because the absence of a Fermi surface precludes a weak-coupling regime where one can extend insights from the Bardeen-Cooper-Schrieffer picture of a…

Superconductivity · Physics 2026-04-17 Tamaghna Hazra , Nishchhal Verma , Jörg Schmalian

A restricted path integral method is proposed to simulate a type of quantum system or Hamiltonian called a sum of controlled few-fermions on a classical computer using Monte Carlo without a numerical sign problem. Then a universality is…

General Physics · Physics 2023-05-23 David H. Wei

Frustration, that is, the impossibility of satisfying the energetic preferences between all spin pairs simultaneously, underlies the complexity of many fundamental properties in spin systems, including the computational difficulty in…

Quantum Physics · Physics 2025-04-08 Zheng-Yang Zhou , Clemens Gneiting , J. Q. You , Franco Nori

Exploiting quantum properties to outperform classical ways of information-processing is an outstanding goal of modern physics. A promising route is quantum simulation, which aims at implementing relevant and computationally hard problems in…

An array of planar Penning traps, holding single electrons, can realize an artificial molecule suitable for NMR-like quantum information processing. The effective spin-spin coupling is accomplished by applying a magnetic field gradient,…

Quantum Physics · Physics 2015-06-26 G. Ciaramicoli , F. Galve , I. Marzoli , P. Tombesi