skip to main content
OSTI.GOV title logo U.S. Department of Energy
Office of Scientific and Technical Information

Title: Infrared dynamics of cold atoms on hot graphene membranes

Authors:
; ;
Publication Date:
Sponsoring Org.:
USDOE
OSTI Identifier:
1258716
Grant/Contract Number:
FG02-08ER46512
Resource Type:
Journal Article: Publisher's Accepted Manuscript
Journal Name:
Physical Review B
Additional Journal Information:
Journal Volume: 93; Journal Issue: 23; Related Information: CHORUS Timestamp: 2016-06-23 11:09:40; Journal ID: ISSN 2469-9950
Publisher:
American Physical Society
Country of Publication:
United States
Language:
English

Citation Formats

Sengupta, Sanghita, Kotov, Valeri N., and Clougherty, Dennis P.. Infrared dynamics of cold atoms on hot graphene membranes. United States: N. p., 2016. Web. doi:10.1103/PhysRevB.93.235437.
Sengupta, Sanghita, Kotov, Valeri N., & Clougherty, Dennis P.. Infrared dynamics of cold atoms on hot graphene membranes. United States. doi:10.1103/PhysRevB.93.235437.
Sengupta, Sanghita, Kotov, Valeri N., and Clougherty, Dennis P.. 2016. "Infrared dynamics of cold atoms on hot graphene membranes". United States. doi:10.1103/PhysRevB.93.235437.
@article{osti_1258716,
title = {Infrared dynamics of cold atoms on hot graphene membranes},
author = {Sengupta, Sanghita and Kotov, Valeri N. and Clougherty, Dennis P.},
abstractNote = {},
doi = {10.1103/PhysRevB.93.235437},
journal = {Physical Review B},
number = 23,
volume = 93,
place = {United States},
year = 2016,
month = 6
}

Journal Article:
Free Publicly Available Full Text
Publisher's Version of Record at 10.1103/PhysRevB.93.235437

Citation Metrics:
Cited by: 1work
Citation information provided by
Web of Science

Save / Share:
  • We study the ground-state properties of the interacting spinless fermions in the p{sub x,y}-orbital bands in the two-dimensional honeycomb optical lattice, which exhibit different features from those in the p{sub z}-orbital system of graphene. In addition to two dispersive bands with Dirac cones, the tight-binding band structure exhibits another two completely flat bands over the entire Brillouin zone. With the realistic sinusoidal optical potential, the flat bands acquire a finite but much smaller bandwidth compared to the dispersive bands. The band flatness dramatically enhanced interaction effects giving rise to various charge and bond ordered states at commensurate fillings of n=(i/6)(i=1-6).more » At n=(1/6), the many-body ground states can be exactly solved as the close-packed hexagon states which can be stabilized even in the weakly interacting regime. The dimerization of bonding strength occurs at both n=(1/2) and (5/6), and the latter case is accompanied with the charge-density wave of holes. The trimerization of bonding strength and charge inhomogeneity appear at n=(1/3),(2/3). These crystalline orders exhibit themselves in the noise correlations of the time-of-flight spectra.« less
  • An accurate system-bath model to investigate the quantum dynamics of hydrogen atoms chemisorbed on graphene is presented. The system comprises a hydrogen atom and the carbon atom from graphene that forms the covalent bond, and it is described by a previously developed 4D potential energy surface based on density functional theory ab initio data. The bath describes the rest of the carbon lattice and is obtained from an empirical force field through inversion of a classical equilibrium correlation function describing the hydrogen motion. By construction, model building easily accommodates improvements coming from the use of higher level electronic structure theorymore » for the system. Further, it is well suited to a determination of the system-environment coupling by means of ab initio molecular dynamics. This paper details the system-bath modeling and shows its application to the quantum dynamics of vibrational relaxation of a chemisorbed hydrogen atom, which is here investigated at T = 0 K with the help of the multi-configuration time-dependent Hartree method. Paper II deals with the sticking dynamics.« less
  • Following our recent system-bath modeling of the interaction between a hydrogen atom and a graphene surface [Bonfanti et al., J. Chem. Phys. 143, 124703 (2015)], we present the results of converged quantum scattering calculations on the activated sticking dynamics. The focus of this study is the collinear scattering on a surface at zero temperature, which is treated with high-dimensional wavepacket propagations with the multi-configuration time-dependent Hartree method. At low collision energies, barrier-crossing dominates the sticking and any projectile that overcomes the barrier gets trapped in the chemisorption well. However, at high collision energies, energy transfer to the surface is amore » limiting factor, and fast H atoms hardly dissipate their excess energy and stick on the surface. As a consequence, the sticking coefficient is maximum (∼0.65) at an energy which is about one and half larger than the barrier height. Comparison of the results with classical and quasi-classical calculations shows that quantum fluctuations of the lattice play a primary role in the dynamics. A simple impulsive model describing the collision of a classical projectile with a quantum surface is developed which reproduces the quantum results remarkably well for all but the lowest energies, thereby capturing the essential physics of the activated sticking dynamics investigated.« less
  • Cited by 9
  • Cited by 8