Improving the efficiency of quantum impurity solvers

Abstract

Quantum impurity systems displays the hallmarks of strong electronic correlation, and are increasingly relevant to modern electronic structure theory due to the development of methods such as Dynamical Mean Field Theory (DMFT). Developing efficient strategies to solve impurity problems is therefore critical in regards to the continued development of DMFT as a versatile and accurate electronic structure tool. Herein, it is reported that a family of basis sets derived from the Schmidt decomposition of a product state leads to a compact description of their ground states. Spectral functions, computed from such ground states reflect the ubiquitous Kondo screening of the impurity for the Single Impurity Anderson Model, and that of the screened phase of its Two Impurity extension. These calculations suggest that these relatively under-explored choices of basis could be of general interest for a range of quantum impurity solvers, whenever Kondo screening effects are important to the description of the ground state.

Date of Award	10 Dec 2024
Original language	English
Awarding Institution	University of Bristol
Supervisor	Stephen R Clark (Supervisor)