5 papers
Emergent Non-Markovian Nonlinear Qubit From Collective Spin Interactions
Gregory T. Carroll, Michael R. Geller, Andre Erpenbeck
Open-system descriptions are typically introduced by coupling a quantum system to an external environment. Here we show that a closed interacting many-body system can itself genera…
Validity and Limits of Low Order Hybridization Expansion Approaches for Multi-Orbital Systems
Dolev Goldberger, Ido Zemach, Lei Zhang +4
Low-order hybridization expansion methods such as the non-crossing approximation (NCA) and the one-crossing approximation (OCA) are widely used impurity solvers in the study of str…
Compact representation and long-time extrapolation of real-time data for quantum systems using the ESPRIT algorithm
Andre Erpenbeck, Yuanran Zhu, Yang Yu +6
Representing real-time data as a sum of complex exponentials provides a compact form that enables both denoising and extrapolation. As a fully data-driven method, the Estimation of…
Inchworm tensor train hybridization expansion quantum impurity solver
Yang Yu, André Erpenbeck, Dominika Zgid +3
The investigation of quantum impurity models plays a crucial role in condensed matter physics because of their wide-ranging applications, such as embedding theories and transport p…
Minimal pole representation for spectral functions
Lei Zhang, André Erpenbeck, Yang Yu +1
Representing spectral densities, real-frequency, and real-time Green's functions of continuous systems by a small discrete set of complex poles is an ubiquitous problem in condense…