Zobrazeno 1 - 10
of 191
pro vyhledávání: '"Großmann, Frank"'
Autor:
Qiao, Yulong, Grossmann, Frank
Multi-mode Glauber coherent states (MMGS) as well as Bloch states with zero quasi-momentum, which are a special case of generalized coherent states (GCS), are frequently used to describe condensed phases of bosonic many-body systems. The difference o
Externí odkaz:
http://arxiv.org/abs/2404.05471
Autor:
Grossmann, Frank
Numerical solutions of the time-dependent Schr\"odinger equation based on the variational principle may offer physical insight that cannot be gained by a solution using fixed grids in position and momentum space. Here we focus on the tunneling dynami
Externí odkaz:
http://arxiv.org/abs/2402.13847
Autor:
Qiao, Yulong, Grossmann, Frank
The mean-field approach to two-site Bose-Hubbard systems is well established and leads to nonlinear classical equations of motion for the population imbalance and the phase difference. It can, e.g., be based on the representation of the solution of t
Externí odkaz:
http://arxiv.org/abs/2302.05349
Publikováno v:
SciPost Phys. 15, 007 (2023)
The full state vector of boson sampling is generated by passing S single photons through beam splitters of M modes. The initial Fock state is expressed withgeneralized coherent states, and an exact application of the unitary evolution becomes possibl
Externí odkaz:
http://arxiv.org/abs/2210.09915
Publikováno v:
J. Chem. Phys. 156, 214702 (2022)
Vibrational dynamics of adsorbates near surfaces plays both an important role for applied surface science and as model lab for studying fundamental problems of open quantum systems. We employ a previously developed model for the relaxation of a D-Si-
Externí odkaz:
http://arxiv.org/abs/2203.09820
We investigate the longstanding problem of thermalization of quantum systems coupled to an environment by focusing on a bistable quartic oscillator interacting with a finite number of harmonic oscillators. In order to overcome the exponential wall th
Externí odkaz:
http://arxiv.org/abs/2111.10181
Employing the time-dependent variational principle combined with the multiple Davydov $\mathrm{D}_2$ Ansatz, we investigate Landau-Zener (LZ) transitions in a qubit coupled to a photon mode with various initial photon states at zero temperature. Than
Externí odkaz:
http://arxiv.org/abs/2103.05307
Autor:
Qiao, Yulong, Grossmann, Frank
Publikováno v:
Phys. Rev. A 103, 042209 (2021)
We propose a variational approach to the dynamics of the Bose-Hubbard model beyond the mean field approximation. To develop a numerical scheme, we use a discrete overcomplete set of Glauber coherent states and its connection to the generalized cohere
Externí odkaz:
http://arxiv.org/abs/2102.05934
Autor:
Werther, Michael, Grossmann, Frank
Publikováno v:
Phys. Rev. B 101, 174315 (2020)
Due to the exponential increase of the numerical effort with the number of degrees of freedom, moving basis functions have a long history in quantum dynamics. In addition, spawning of new basis functions is routinely applied. Here we advocate the opp
Externí odkaz:
http://arxiv.org/abs/1908.08240
Autor:
Buchholz, Max, Fallacara, Erika, Gottwald, Fabian, Ceotto, Michele, Grossmann, Frank, Ivanov, Sergei D.
Semiclassical techniques constitute a promising route to approximate quantum dynamics based on classical trajectories starting from a quantum-mechanically correct distribution. One of their main drawbacks is the so-called zero-point energy (ZPE) leak
Externí odkaz:
http://arxiv.org/abs/1805.01686