scholarly journals Out-of-equilibrium dynamics in a quantum impurity model: Numerics for particle transport and entanglement entropy

2017 ◽  
Vol 96 (19) ◽  
Author(s):  
Kemal Bidzhiev ◽  
Grégoire Misguich
Keyword(s):  
Particle Transport ◽  
Entanglement Entropy ◽  
Equilibrium Dynamics ◽  
Impurity Model ◽  
Quantum Impurity

scholarly journals Information dynamics in a model with Hilbert space fragmentation

2021 ◽  
Vol 11 (4) ◽  
Author(s):  
Dominik Hahn ◽  
Paul A. McClarty ◽  
David J. Luitz
Keyword(s):  
Hilbert Space ◽  
Entanglement Entropy ◽  
Long Distance ◽  
Information Dynamics ◽  
Geometrically Frustrated ◽  
Equilibrium Dynamics ◽  
Maximum Value ◽  
Far From Equilibrium ◽  
Quench Dynamics ◽  
Frustrated Spin

The fully frustrated ladder – a quasi-1D geometrically frustrated spin one half Heisenberg model – is non-integrable with local conserved quantities on rungs of the ladder, inducing the local fragmentation of the Hilbert space into sectors composed of singlets and triplets on rungs. We explore the far-from-equilibrium dynamics of this model through the entanglement entropy and out-of-time-ordered correlators (OTOC). The post-quench dynamics of the entanglement entropy is highly anomalous as it shows clear non-damped revivals that emerge from short connected chunks of triplets. We find that the maximum value of the entropy follows from a picture where coherences between different fragments co-exist with perfect thermalization within each fragment. This means that the eigenstate thermalization hypothesis holds within all sufficiently large Hilbert space fragments. The OTOC shows short distance oscillations arising from short coupled fragments, which become decoherent at longer distances, and a sub-ballistic spreading and long distance exponential decay stemming from an emergent length scale tied to fragmentation.

scholarly journals Quantum impurity model for anyons

2020 ◽  
Vol 102 (14) ◽  
Author(s):  
E. Yakaboylu ◽  
A. Ghazaryan ◽  
D. Lundholm ◽  
N. Rougerie ◽  
M. Lemeshko ◽  
...  
Keyword(s):  
Impurity Model ◽  
Quantum Impurity

scholarly journals Strong-coupling solver for the quantum impurity model

2005 ◽  
Vol 72 (4) ◽  
Author(s):  
Xi Dai ◽  
Kristjan Haule ◽  
Gabriel Kotliar
Keyword(s):  
Strong Coupling ◽  
Impurity Model ◽  
Quantum Impurity

scholarly journals Solution to the sign problem in a frustrated quantum impurity model

2017 ◽  
Vol 376 ◽  
pp. 63-75 ◽  
Author(s):  
Connor T. Hann ◽  
Emilie Huffman ◽  
Shailesh Chandrasekharan
Keyword(s):  
Impurity Model ◽  
Sign Problem ◽  
Quantum Impurity

scholarly journals Entanglement entropy in quantum impurity systems and systems with boundaries

2009 ◽  
Vol 42 (50) ◽  
pp. 504009 ◽  
Author(s):  
Ian Affleck ◽  
Nicolas Laflorencie ◽  
Erik S Sørensen
Keyword(s):  
Entanglement Entropy ◽  
Quantum Impurity

scholarly journals Maximally Localized Dynamical Quantum Embedding for Solving Many-Body Correlated Systems

2020 ◽  
Author(s):  
Carla Lupo ◽  
Wai Hei Terence Tze ◽  
Francois Jamet ◽  
Ivan Rungger ◽  
Cedric Weber
Keyword(s):  
Degrees Of Freedom ◽  
Mean Field Theory ◽  
Mean Field ◽  
Many Body ◽  
Correlated Systems ◽  
Impurity Model ◽  
Quantum Impurity ◽  
Diagonalization Method ◽  
Large Benefit ◽  
Exact Diagonalization Method

Abstract We present a quantum embedding methodology to resolve the Anderson impurity model in the context of dynamical mean-field theory, based on an extended exact diagonalization method. Our method provides a maximally localized quantum impurity model, where the non-local components of the correlation potential remain minimal. This comes at a large benefit, as the environment used in the quantum embedding approach is described by propagating correlated electrons and hence offers an exponentially increasing number of degrees of freedom for the embedding mapping, in contrast to traditional free-electron representation where the scaling is linear. We report that quantum impurity models with as few as 3 bath sites can reproduce both the Mott transition and the Kondo physics, thus opening a more accessible route to the description of time-dependent phenomena. Finally, we obtain excellent agreement for dynamical magnetic susceptibilities, poising this approach as a candidate to describe 2-particle excitations such as excitons in correlated systems. We expect that our approach will be highly beneficial for the implementation of embedding algorithms on quantum computers, as it allows for a fine description of the correlation in materials with a reduced number of required qubits.

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