117 research outputs found
Electronic energy relaxation and transition frequency jumps of single molecules at 30 mK
Transition frequency jumps for single terrylene molecules in a polyethylene matrix caused by resonant laser irradiation are investigated at 30 mK. These jumps are not accompanied by substantial sample heating. A model for the effect is: proposed, based on the interaction of tunneling two-level systems (TLSs) surrounding the single molecule with high-energy nonthermal phonons emitted by the molecule during electronic energy relaxation. The radius of the effective interaction volume is estimated to be r(m) approximate to 12.5 nm, and the interaction cross section for nonequilibrium phonon -TLS scattering is estimated as similar to 10(-22) cm(-2)
Time-dependent single molecule spectral lines
A general conceptual problem of time-dependent single molecule spectra is discussed theoretically in the framework of recently developed intensity-time-frequency correlation spectroscopy. It is shown that the new method is closely related to a "gedanken" three-pulse photon echo experiment done on an ensemble of identical molecules interacting with statistically identical microscopic environments. The correlation function is an integral transform (under certain conditions a Fourier transform) of the echo amplitude as a function of the delay between the first and the second pulses. [S0163-1829(99)10907-X]
Development of a data model and a prototype information sharing platform for DEMAT machine tools
L\'evy Distribution of Single Molecule Line Shape Cumulants in Low Temperature Glass
We investigate the distribution of single molecule line shape cumulants,
, in low temperature glasses based on the sudden jump,
standard tunneling model. We find that the cumulants are described by L\'evy
stable laws, thus generalized central limit theorem is applicable for this
problem.Comment: 5 pages, 3 figure
Efficient coupling of photons to a single molecule and the observation of its resonance fluorescence
Single dye molecules at cryogenic temperatures display many spectroscopic
phenomena known from free atoms and are thus promising candidates for
fundamental quantum optical studies. However, the existing techniques for the
detection of single molecules have either sacrificed the information on the
coherence of the excited state or have been inefficient. Here we show that
these problems can be addressed by focusing the excitation light near to the
absorption cross section of a molecule. Our detection scheme allows us to
explore resonance fluorescence over 9 orders of magnitude of excitation
intensity and to separate its coherent and incoherent parts. In the strong
excitation regime, we demonstrate the first observation of the Mollow triplet
from a single solid-state emitter. Under weak excitation we report the
detection of a single molecule with an incident power as faint as 150 attoWatt,
paving the way for studying nonlinear effects with only a few photons.Comment: 6 figure
Ultrafast electronic read-out of diamond NV centers coupled to graphene
Nonradiative transfer processes are often regarded as loss channels for an
optical emitter1, since they are inherently difficult to be experimentally
accessed. Recently, it has been shown that emitters, such as fluorophores and
nitrogen vacancy centers in diamond, can exhibit a strong nonradiative energy
transfer to graphene. So far, the energy of the transferred electronic
excitations has been considered to be lost within the electron bath of the
graphene. Here, we demonstrate that the trans-ferred excitations can be
read-out by detecting corresponding currents with picosecond time resolution.
We electrically detect the spin of nitrogen vacancy centers in diamond
electronically and con-trol the nonradiative transfer to graphene by electron
spin resonance. Our results open the avenue for incorporating nitrogen vacancy
centers as spin qubits into ultrafast electronic circuits and for harvesting
non-radiative transfer processes electronically
- …