1,155 research outputs found
An Exact Solution for the Lattice Gas Model in One Dimension
A simple method to obtain a canonical partition function for one dimensional
lattice gas model is presented. The simplification is based upon rewriting a
sum over all possible configurations to a sum over numbers of clusters in the
system.Comment: 6 pages, LaTe
Coherent coupling of molecular resonators with a micro-cavity mode
The optical hybridization of the electronic states in strongly coupled
molecule-cavity systems have revealed unique properties such as lasing, room
temperature polariton condensation, and the modification of excited electronic
landscapes involved in molecular isomerization. Here we show that molecular
vibrational modes of the electronic ground state can also be coherently coupled
with a micro-cavity mode at room temperature, given the low vibrational thermal
occupation factors associated with molecular vibrations, and the collective
coupling of a large ensemble of molecules immersed within the cavity mode
volume. This enables the enhancement of the collective Rabi-exchange rate with
respect to the single oscillator coupling strength. The possibility of inducing
large shifts in the vibrational frequency of selected molecular bonds should
have immediate consequences for chemistry.Comment: 22 pages, 6 figures (including Supplementary Information file
Multiple Rabi Splittings under Ultra-Strong Vibrational Coupling
From the high vibrational dipolar strength offered by molecular liquids, we
demonstrate that a molecular vibration can be ultra-strongly coupled to
multiple IR cavity modes, with Rabi splittings reaching of the vibration
frequencies. As a proof of the ultra-strong coupling regime, our experimental
data unambiguously reveal the contributions to the polaritonic dynamics coming
from the anti-resonant terms in the interaction energy and from the dipolar
self-energy of the molecular vibrations themselves. In particular, we measure
the opening of a genuine vibrational polaritonic bandgap of ca. meV. We
also demonstrate that the multimode splitting effect defines a whole
vibrational ladder of heavy polaritonic states perfectly resolved. These
findings reveal the broad possibilities in the vibrational ultra-strong
coupling regime which impact both the optical and the molecular properties of
such coupled systems, in particular in the context of mode-selective chemistry.Comment: 10 pages, 9 figure
Ensemble-induced strong light-matter coupling of a single quantum emitter
We discuss a technique to strongly couple a single target quantum emitter to
a cavity mode, which is enabled by virtual excitations of a nearby mesoscopic
ensemble of emitters. A collective coupling of the latter to both the cavity
and the target emitter induces strong photon non-linearities in addition to
polariton formation, in contrast to common schemes for ensemble strong
coupling. We demonstrate that strong coupling at the level of a single emitter
can be engineered via coherent and dissipative dipolar interactions with the
ensemble, and provide realistic parameters for a possible implementation with
SiV defects in diamond. Our scheme can find applications, amongst others,
in quantum information processing or in the field of cavity-assisted quantum
chemistry.Comment: 13 pages, 6 figures; substantially revised manuscript; see
arXiv:1912.12703 for mathematical derivation
Quantum Conductance Steps in Solutions of Multiwalled Carbon Nanotubes
We have prepared solutions of multiwalled carbon nanotubes in Aroclor 1254, a
mixture of polychlorinated biphenyls. The solutions are stable at room
temperature. Transport measurements were performed using a scanning--tunneling
probe on a sample prepared by spin--coating of the solution on gold substrates.
Conductance steps were clearly seen. An histogram of a high number of traces
shows maximum peaks at integer values of the conductance quantum , demonstrating ballistic transport at room temperature along the carbon
nanotube over distances longer than .Comment: 4 pages and 2 figure
Dimerization structures on the metallic and semiconducting fullerene tubules with half-filled electrons
Possible dimerization patterns and electronic structures in fullerene tubules
as the one-dimensional pi-conjugated systems are studied with the extended
Su-Schrieffer-Heeger model. We assume various lattice geometries, including
helical and nonhelical tubules. The model is solved for the half-filling case
of -electrons. (1) When the undimerized systems do not have a gap, the
Kekule structures prone to occur. The energy gap is of the order of the room
temperatures at most and metallic properties would be expected. (2) If the
undimerized systems have a large gap (about 1eV), the most stable structures
are the chain-like distortions where the direction of the arranged
trans-polyacetylene chains is along almost the tubular axis. The electronic
structures are ofsemiconductors due to the large gap.Comment: submitted to Phys. Rev. B, pages 15, figures 1
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