Laserlike Vibrational Instability in Rectifying Molecular Conductors

TY - JOUR

T1 - Laserlike Vibrational Instability in Rectifying Molecular Conductors

AU - Lu, Jing-Tao

AU - Hedegård, Per

AU - Brandbyge, Mads

PY - 2011/7/20

Y1 - 2011/7/20

N2 - We study the damping of molecular vibrations due to electron-hole pair excitations in donor-acceptor (D-A) type molecular rectifiers. At finite voltage additional nonequilibrium electron-hole pair excitations involving both electrodes become possible, and contribute to the stimulated emission and absorption of phonons. We point out a generic mechanism for D-A molecules, where the stimulated emission can dominate beyond a certain voltage due to the inverted position of the D and A quantum resonances. This leads to current-driven amplification (negative damping) of the phonons similar to laser action. We investigate the effect in realistic molecular rectifier structures using first-principles calculations.

AB - We study the damping of molecular vibrations due to electron-hole pair excitations in donor-acceptor (D-A) type molecular rectifiers. At finite voltage additional nonequilibrium electron-hole pair excitations involving both electrodes become possible, and contribute to the stimulated emission and absorption of phonons. We point out a generic mechanism for D-A molecules, where the stimulated emission can dominate beyond a certain voltage due to the inverted position of the D and A quantum resonances. This leads to current-driven amplification (negative damping) of the phonons similar to laser action. We investigate the effect in realistic molecular rectifier structures using first-principles calculations.

U2 - 10.1103/PhysRevLett.107.046801

DO - 10.1103/PhysRevLett.107.046801

M3 - Journal article

SN - 0031-9007

VL - 107

SP - 046801

JO - Physical Review Letters

JF - Physical Review Letters

IS - 4

ER -