TY - JOUR
T1 - Efficient compression of the environment of an open quantum system
AU - Booth, George
PY - 2020/10/6
Y1 - 2020/10/6
N2 - In order to simulate open quantum systems, many approaches (such as Hamiltonian-based solvers in dynamical mean-field theory) aim for a reproduction of a desired environment spectral density in terms of a discrete set of bath states, mimicking the open system as a larger closed problem. Existing strategies to find a compressed representation of the environment for this purpose can be numerically demanding, or lack the compactness and systematic improvability required for an accurate description of the system propagator. We propose a method in which bath orbitals are constructed explicitly by an algebraic construction based on the Schmidt decomposition of response functions, efficiently and systematically compressing the description of the full environment. These resulting bath orbitals are designed to directly reproduce the system Green's function, not hybridization, which allows for consideration of the relevant system energy scales. This results in an accurate and efficient truncation of the environment, with applications in a wide range of numerical simulations of open quantum systems.
AB - In order to simulate open quantum systems, many approaches (such as Hamiltonian-based solvers in dynamical mean-field theory) aim for a reproduction of a desired environment spectral density in terms of a discrete set of bath states, mimicking the open system as a larger closed problem. Existing strategies to find a compressed representation of the environment for this purpose can be numerically demanding, or lack the compactness and systematic improvability required for an accurate description of the system propagator. We propose a method in which bath orbitals are constructed explicitly by an algebraic construction based on the Schmidt decomposition of response functions, efficiently and systematically compressing the description of the full environment. These resulting bath orbitals are designed to directly reproduce the system Green's function, not hybridization, which allows for consideration of the relevant system energy scales. This results in an accurate and efficient truncation of the environment, with applications in a wide range of numerical simulations of open quantum systems.
UR - http://www.scopus.com/inward/record.url?scp=85094612282&partnerID=8YFLogxK
U2 - 10.1103/PhysRevB.102.165107
DO - 10.1103/PhysRevB.102.165107
M3 - Article
SN - 1098-0121
VL - 102
SP - 165107
JO - Physical Review B (Condensed Matter and Materials Physics)
JF - Physical Review B (Condensed Matter and Materials Physics)
IS - 16
M1 - 165107
ER -