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@ARTICLE{Nghiem:154993,
author = {Nghiem, Hoa and Costi, Theodoulos},
title = {{T}ime-dependent numerical renormalization group method for
multiple quenches: {A}pplication to general pulses and
periodic driving},
journal = {Physical review / B},
volume = {90},
number = {3},
issn = {1098-0121},
address = {College Park, Md.},
publisher = {APS},
reportid = {FZJ-2014-04192},
pages = {035129},
year = {2014},
abstract = {The time-dependent numerical renormalization group method
(TDNRG) [Anders et al., Phys. Rev. Lett. 95, 196801 (2005)]
was recently generalized to multiple quenches and arbitrary
finite temperatures [Nghiem et al., Phys. Rev. B 89, 075118
(2014)] by using the full density matrix approach
[Weichselbaum et al., Phys. Rev. Lett. 99, 076402 (2007)].
The formalism rests solely on the numerical renormalization
group (NRG) approximation. In this paper, we numerically
implement this formalism to study the response of a quantum
impurity system to a general pulse and to periodic driving,
in which a smooth pulse or a periodic train of pulses is
approximated by a sufficient number of quenches. We show how
the NRG approximation affects the trace of the projected
density matrices and the continuity of the time evolution of
a local observable. We also investigate the long-time limit
of a local observable upon switching from a given initial
state to a given final state as a function of both the pulse
shape and the switch-on time, finding that this limit is
improved for smoother pulse shapes and longer switch-on
times. This lends support to our earlier suggestion that the
long-time limit of observables, following a quench between a
given initial state and a given final state, can be improved
by replacing a sudden large and instantaneous quench by a
sequence of smaller ones acting over a finite time interval:
longer switch-on times and smoother pulses, i.e., increased
adiabaticity, favor relaxation of the system to its correct
thermodynamic long-time limit. For the case of periodic
driving, we compare the TDNRG results to the exact analytic
ones for the noninteracting resonant level model, finding
better agreement at short to intermediate time scales in the
case of smoother driving fields. Finally, we demonstrate the
validity of the multiple-quench TDNRG formalism for
arbitrary temperatures by studying the time evolution of the
occupation number in the interacting Anderson impurity model
in response to a periodic switching of the local level from
the mixed valence to the Kondo regime at low, intermediate,
and high temperatures.},
cin = {IAS-3 / PGI-2 / JARA-HPC},
ddc = {530},
cid = {I:(DE-Juel1)IAS-3-20090406 / I:(DE-Juel1)PGI-2-20110106 /
$I:(DE-82)080012_20140620$},
pnm = {424 - Exploratory materials and phenomena (POF2-424) /
Thermoelectric properties of molecular quantum dots and
time-dependent response of quantum dots $(jiff23_20140501)$},
pid = {G:(DE-HGF)POF2-424 / $G:(DE-Juel1)jiff23_20140501$},
typ = {PUB:(DE-HGF)16},
UT = {WOS:000339481800002},
doi = {10.1103/PhysRevB.90.035129},
url = {https://juser.fz-juelich.de/record/154993},
}