TY  - JOUR
A1  - Tremblay, Jean Christophe
A1  - Monturet, Serge
A1  - Saalfrank, Peter
T1  - The Effects of electron-hole pair coupling on the infrared laser-controlled vibrational excitation of NO on Au(111)
JF  - The journal of physical chemistry : A, Molecules, spectroscopy, kinetics, environment & general theory
N2  - In this work, we present theoretical simulations of laser-driven vibrational control of NO adsorbed on a gold surface. Our goal is to tailor laser pulses to selectively excite specific modes and vibrational eigenstates, as well as to favor photodesorption of the adsorbed molecule. To this end, various control schemes and algorithms are applied. For adsorbates at metallic surfaces, the creation of electron hole pairs in the substrate is known to play a dominant role in the transfer of energy from the system to the surroundings. These nonadiabatic couplings are included perturbatively in our reduced density matrix simulations using a generalization of the state-resolved position-dependent anharmonic rate model we recently introduced. An extension of the reduced density matrix is also proposed to provide a sound model for photodesorption in dissipative systems.
Y1  - 2011
U6  - https://doi.org/10.1021/jp205902k
SN  - 1089-5639
VL  - 115
IS  - 39
SP  - 10698
EP  - 10707
PB  - American Chemical Society
CY  - Washington
ER  - 
TY  - JOUR
A1  - Malic, E.
A1  - Weber, C.
A1  - Richter, M.
A1  - Atalla, V.
A1  - Klamroth, Tillmann
A1  - Saalfrank, Peter
A1  - Reich, Sebastian
A1  - Knorr, A.
T1  - Microscopic model of the optical absorption of carbon nanotubes functionalized with molecular spiropyran photoswitches
JF  - Physical review letters
N2  - The adsorption of molecules to the surface of carbon nanostructures opens a new field of hybrid systems with distinct and controllable properties. We present a microscopic study of the optical absorption in carbon nanotubes functionalized with molecular spiropyran photoswitches. The switching process induces a change in the dipole moment leading to a significant coupling to the charge carriers in the nanotube. As a result, the absorption spectra of functionalized tubes reveal a considerable redshift of transition energies depending on the switching state of the spiropyran molecule. Our results suggest that carbon nanotubes are excellent substrates for the optical readout of spiropyran-based molecular switches. The gained insights can be applied to other noncovalently functionalized one-dimensional nanostructures in an externally induced dipole field.
Y1  - 2011
U6  - https://doi.org/10.1103/PhysRevLett.106.097401
SN  - 0031-9007
VL  - 106
IS  - 9
PB  - American Physical Society
CY  - College Park
ER  - 
TY  - JOUR
A1  - Floss, Gereon
A1  - Klamroth, Tillmann
A1  - Saalfrank, Peter
T1  - Laser-controlled switching of molecular arrays in an dissipative environment
JF  - Physical review : B, Condensed matter and materials physics
N2  - The optical switching of molecular ensembles in a dissipative environment is a subject of various fields of chemical physics and physical chemistry. Here we try to switch arrays of molecules from a stable collective ground state to a state in which all molecules have been transferred to another stable higher-energy configuration. In our model switching proceeds through electronically excited intermediates which are coherently coupled to each other through dipolar interactions, and which decay incoherently within a finite lifetime by coupling to a dissipative environment. The model is quite general, but parameters are chosen to roughly resemble the all-trans -> all-cis isomerization of an array of azobenzene molecules on a surface. Using analytical and optimal control pulses and the concept of "laser distillation," we demonstrate that for various aggregates (dimers up to hexamers), controlled and complete switching should be possible.
Y1  - 2011
U6  - https://doi.org/10.1103/PhysRevB.83.104301
SN  - 1098-0121
VL  - 83
IS  - 10
PB  - American Physical Society
CY  - College Park
ER  -