This title appears in the Scientific Report :
2018
Please use the identifier:
http://dx.doi.org/10.1103/PhysRevB.98.155107 in citations.
Please use the identifier: http://hdl.handle.net/2128/19754 in citations.
Time-dependent numerical renormalization group method for multiple quenches: Towards exact results for the long-time limit of thermodynamic observables and spectral functions
Time-dependent numerical renormalization group method for multiple quenches: Towards exact results for the long-time limit of thermodynamic observables and spectral functions
We develop an alternative time-dependent numerical renormalization group (TDNRG) formalism for multiple quenches and implement it to study the response of a quantum impurity system to a general pulse. Within this approach, we reduce the contribution of the NRG approximation to numerical errors in th...
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Personal Name(s): | Nghiem, H. T. M. |
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Costi, Theodoulos (Corresponding author) | |
Contributing Institute: |
JARA - HPC; JARA-HPC Theoretische Nanoelektronik; IAS-3 |
Published in: | Physical Review B Physical review / B, 98 98 (2018 2018) 15 15, S. 155107 155107 |
Imprint: |
Woodbury, NY
Inst.
2018
|
DOI: |
10.1103/PhysRevB.98.155107 |
Document Type: |
Journal Article |
Research Program: |
Thermoelectric properties of molecular quantum dots and time-dependent response of quantum dots Controlling Spin-Based Phenomena |
Link: |
OpenAccess OpenAccess |
Publikationsportal JuSER |
Please use the identifier: http://hdl.handle.net/2128/19754 in citations.
We develop an alternative time-dependent numerical renormalization group (TDNRG) formalism for multiple quenches and implement it to study the response of a quantum impurity system to a general pulse. Within this approach, we reduce the contribution of the NRG approximation to numerical errors in the time evolution of observables by a formulation that avoids the use of the generalized overlap matrix elements in our previous multiple-quench TDNRG formalism [Nghiem et al., Phys. Rev. B 89, 075118 (2014); Phys. Rev. B 90, 035129 (2014)]. We demonstrate that the formalism yields a smaller cumulative error in the trace of the projected density matrix as a function of time and a smaller discontinuity of local observables between quenches than in our previous approach. Moreover, by increasing the switch-on time, the time between the first and last quench of the discretized pulse, the long-time limit of observables systematically converges to its expected value in the final state, i.e., the more adiabatic the switching, the more accurately is the long-time limit recovered. The present formalism can be straightforwardly extended to infinite switch-on times. We show that this yields highly accurate results for the long-time limit of both thermodynamic observables and spectral functions, and overcomes the significant errors within the single quench formalism [Anders et al., Phys. Rev. Lett. 95, 196801 (2005); Nghiem et al., Phys. Rev. Lett. 119, 156601 (2017)]. This improvement provides a first step towards an accurate description of nonequilibrium steady states of quantum impurity systems, e.g., within the scattering states NRG approach [Anders, Phys. Rev. Lett. 101, 066804 (2008)]. |