Negative-Temperature State Formed and Interactions Inverted by Symmetric Monocycle Optical Pulse Excitation
Abstract
The excited state dynamics of correlated electron and electron-phonon systems triggered by an oscillating electric-field pulse of large amplitude are theoretically investigated. A "negative-temperature" state and inversion of electron-electron and electron-phonon interactions are induced even by a symmetric monocycle pulse. This fact is numerically demonstrated, using the exact diagonalization method, in a band-insulator phase of one-dimensional three-quarter-filled strongly dimerized extended Peierls-Hubbard and Holstein models. When the total-energy increment is maximized as a function of the electric field amplitude, the occupancy of the bonding and antibonding orbitals is inverted to produce a negative-temperature state. Around this state, the dependences of time-averaged electron-electron and electron-phonon correlation functions on interaction parameters are opposite to those in the ground state.
Keywords
Cite
@article{arxiv.1503.03106,
title = {Negative-Temperature State Formed and Interactions Inverted by Symmetric Monocycle Optical Pulse Excitation},
author = {Kenji Yonemitsu and Keita Nishioka},
journal= {arXiv preprint arXiv:1503.03106},
year = {2015}
}
Comments
21 pages, 9 figures, accepted for publication in J. Phys. Soc. Jpn