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We study the non-equilibrium dynamics of a spinful single-orbital quantum dot with an incorporated quantum mechanical spin-1/2 magnetic impurity. Due to the spin degeneracy, double occupancy is allowed, and Coulomb interaction together with…

Mesoscale and Nanoscale Physics · Physics 2012-07-30 Daniel Becker , Stephan Weiss , Michael Thorwart , Daniela Pfannkuche

In this work we analyze the nonequilibrium transport through a quantum impurity (quantum dot or molecule) attached to ferromagnetic leads by using a hybrid numerical renormalization group-time-dependent density matrix renormalization group…

Mesoscale and Nanoscale Physics · Physics 2022-10-05 Anand Manaparambil , Andeas Weichselbaum , Jan von Delft , Ireneusz Weymann , .

We simulate the nonequilibrium dynamics of two generic many-body quantum impurity models by employing the recently developed iterative influence-functional path integral method [Phys. Rev. B {\bf 82}, 205323 (2010)]. This general approach…

Mesoscale and Nanoscale Physics · Physics 2017-09-13 Dvira Segal , Andrew J. Millis , David R. Reichman

Using one-dimensional spin-orbital model as a typical example of quantum spin systems with richer symmetries, we study the effect of an isolated impurity on its low energy dynamics in the gapless phase through bosonization and…

Strongly Correlated Electrons · Physics 2009-10-31 Yu-Wen Lee , Yu-Li Lee

Problems involving quantum impurities, in which one or a few particles are interacting with a macroscopic environment, represent a pervasive paradigm, spanning across atomic, molecular, and condensed-matter physics. In this paper we…

Mesoscale and Nanoscale Physics · Physics 2019-01-31 Xiang Li , Giacomo Bighin , Enderalp Yakaboylu , Mikhail Lemeshko

We present a numerically exact Inchworm Monte Carlo method for equilibrium multiorbital quantum impurity problems with general interactions and hybridizations. We show that the method, originally developed to overcome the dynamical sign…

Strongly Correlated Electrons · Physics 2020-05-25 Eitan Eidelstein , Emanuel Gull , Guy Cohen

Entanglement in J_1-J_2, S=1/2 quantum spin chains with an impurity is studied using analytic methods as well as large scale numerical density matrix renormalization group methods. The entanglement is investigated in terms of the von…

Strongly Correlated Electrons · Physics 2011-11-09 Erik S. Sørensen , Ming-Shyang Chang , Nicolas Laflorencie , Ian Affleck

Important properties of complex quantum many-body systems and their phase diagrams can often already be inferred from the impurity limit. The Bose polaron problem describing an impurity atom immersed in a Bose-Einstein condensate is a…

Quantum Gases · Physics 2024-03-06 Arthur Christianen , J. Ignacio Cirac , Richard Schmidt

Strongly correlated quantum impurity problems appear in a wide variety of contexts ranging from nanoscience and surface physics to material science and the theory of strongly correlated lattice models, where they appear as auxiliary systems…

Strongly Correlated Electrons · Physics 2013-02-19 Hartmut Hafermann , Philipp Werner , Emanuel Gull

We study a quantum impurity coupled to the edge states of a two-dimensional helical topological superconductor, i.e., to a pair of counterpropagating Majorana fermion edge channels with opposite spin polarizations. For an impurity described…

Strongly Correlated Electrons · Physics 2011-11-15 Rok Zitko , Pascal Simon

We combine quantum optimal control with a variational ansatz based on non-Gaussian states for fast, non-adiabatic preparation of quantum many-body states. We demonstrate this on the example of the spin-boson model, and use a multi-polaron…

Quantum Physics · Physics 2024-07-04 Liam J. Bond , Arghavan Safavi-Naini , Jiří Minář

We describe a variational approach to solving Anderson impurity models by means of exact diagonalization. Optimized parameters of a discretized auxiliary model are obtained on the basis of the Peierls-Feynman-Bogoliubov principle. Thereby,…

Strongly Correlated Electrons · Physics 2015-06-26 M. Schüler , C. Renk , T. O. Wehling

In this paper, we present an extended dissipaton equation of motion for studying the dynamics of electronic impurity systems. Compared with the original theoretical formalism, the quadratic couplings are introduced into the Hamiltonian…

Strongly Correlated Electrons · Physics 2023-07-12 Yu Su , Zi-Hao Chen , Yao Wang , Xiao Zheng , Rui-Xue Xu , YiJing Yan

Whether a small quantum mechanical system is able to equilibrate with its environment once an external local perturbation drives it out of thermal equilibrium is a central question which cuts across many different fields of science. Here we…

Strongly Correlated Electrons · Physics 2012-10-10 Marco Schiró

Quantum impurity models (QIMs) are ubiquitous throughout physics. As simplified toy models they provide crucial insights for understanding more complicated strongly correlated systems, while in their own right are accurate descriptions of…

Statistical Mechanics · Physics 2023-10-12 Colin Rylands , Pasquale Calabrese

By means of a trial wave function, the multi-D$_1$ ansatz, extensive variational calculations with more than ten thousand parameters have been carried out to study quantum phase transitions in the ground states of a two-impurity system…

Statistical Mechanics · Physics 2019-08-27 Nengji Zhou , Yuyu Zhang , Zhiguo Lu , Yang Zhao

Advancing our understanding of non-equilibrium phenomena in quantum many-body systems remains among the greatest challenges in physics. Here, we report on the experimental observation of a paradigmatic many-body problem, namely the…

Strongly correlated quantum impurities under periodic driving can exhibit emergent non-Hermitian phenomena, yet a microscopic understanding has been lacking. We introduce an auxiliary-fermion framework that captures the bath's spin-orbit…

Strongly Correlated Electrons · Physics 2025-12-03 Vinayak M. Kulkarni

We use the framework set up recently to compute non-perturbatively inelastic scattering from quantum impurities [G. Zar\'and {\it et al.}, Phys. Rev. Lett. {\bf 93}, 107204 (2004)] to study the the energy dependence of the single particle…

Strongly Correlated Electrons · Physics 2007-06-18 L. Borda , L. Fritz , N. Andrei , G. Zarand

We consider the dynamics of an impurity atom immersed in an ideal Fermi gas at zero temperature. We focus on the coherent quantum evolution of the impurity following a quench to strong impurity-fermion interactions, where the interactions…

Quantum Gases · Physics 2019-11-25 Meera Parish , Jesper Levinsen