26,074 research outputs found
Transposase mapping identifies the genomic targets of BAP1 in uveal melanoma
Table summarizing the RNA-seq results. Differential gene expression results in BAP1-knockdown compared to control OCM-1A cells are shown from the RNA-seq data. Each row gives the unique Ensembl identifier, gene name, and description for each gene, as well as the log of the fold change (logFC), average expression, adjusted p-value, and linear fold change. (XLSX 1392 kb
Cu/Ag EAM Potential Optimized for Heteroepitaxial Diffusion from ab initio Data
A binary embedded-atom method (EAM) potential is optimized for Cu on Ag(111)
by fitting to ab initio data. The fitting database consists of DFT calculations
of Cu monomers and dimers on Ag(111), specifically their relative energies,
adatom heights, and dimer separations. We start from the Mishin Cu-Ag EAM
potential and first modify the Cu-Ag pair potential to match the FCC/HCP site
energy difference then include Cu-Cu pair potential optimization for the entire
database. The optimized EAM potential reproduce DFT monomer and dimer relative
energies and geometries correctly. In trimer calculations, the potential
produces the DFT relative energy between FCC and HCP trimers, though a
different ground state is predicted. We use the optimized potential to
calculate diffusion barriers for Cu monomers, dimers, and trimers. The
predicted monomer barrier is the same as DFT, while experimental barriers for
monomers and dimers are both lower than predicted here. We attribute the
difference with experiment to the overestimation of surface adsorption energies
by DFT and a simple correction is presented. Our results show that the
optimized Cu-Ag EAM can be applied in the study of larger Cu islands on
Ag(111).Comment: 15 pages, 7 figure
Graphene kirigami as a platform for stretchable and tunable quantum dot arrays
The quantum transport properties of a graphene kirigami similar to those
studied in recent experiments are calculated in the regime of elastic,
reversible deformations. Our results show that, at low electronic densities,
the conductance profile of such structures replicates that of a system of
coupled quantum dots, characterized by a sequence of minibands and stop-gaps.
The conductance and I-V curves have different characteristics in the distinct
stages of elastic deformation that characterize the elongation of these
structures. Notably, the effective coupling between localized states is
strongly reduced in the small elongation stage, whereas in the large elongation
regime the development of strong, localized pseudomagnetic field barriers can
reinforce the coupling and reestablish resonant tunneling across the kirigami.
This provides an interesting example of interplay between geometry and
pseudomagnetic field-induced confinement. The alternating miniband and
stop-gaps in the transmission lead to I-V characteristics with negative
differential conductance in well defined energy/doping ranges. These effects
should be stable in a realistic scenario that includes edge roughness and
Coulomb interactions, as these are expected to further promote localization of
states at low energies in narrow segments of graphene nanostructures.Comment: 10 pages, 10 figure
Transformation Optics Approach to Plasmon-Exciton Strong Coupling in Nanocavities
We investigate the conditions yielding plasmon-exciton strong coupling at the
single emitter level in the gap between two metal nanoparticles. A
quasi-analytical transformation optics approach is developed that makes
possible a thorough exploration of this hybrid system incorporating the full
richness of its plasmonic spectrum. This allows us to reveal that by placing
the emitter away from the cavity center, its coupling to multipolar dark modes
of both even and odd parity increases remarkably. This way, reversible dynamics
in the population of the quantum emitter takes place in feasible
implementations of this archetypal nanocavity.Comment: 5 pages, 4 figure
Quantum key distribution with "dual detectors"
To improve the performance of a quantum key distribution (QKD) system, high
speed, low dark count single photon detectors (or low noise homodyne detectors)
are required. However, in practice, a fast detector is usually noisy. Here, we
propose a "dual detectors" method to improve the performance of a practical QKD
system with realistic detectors: the legitimate receiver randomly uses either a
fast (but noisy) detector or a quiet (but slow) detector to measure the
incoming quantum signals. The measurement results from the quiet detector can
be used to bound eavesdropper's information, while the measurement results from
the fast detector are used to generate secure key. We apply this idea to
various QKD protocols. Simulation results demonstrate significant improvements
in both BB84 protocol with ideal single photon source and Gaussian-modulated
coherent states (GMCS) protocol; while for decoy-state BB84 protocol with weak
coherent source, the improvement is moderate. We also discuss various practical
issues in implementing the "dual detectors" scheme.Comment: 22 pages, 9 figure
Landau level spectroscopy of surface states in the topological insulator BiSb via magneto-optics
We have performed broad-band zero-field and magneto-infrared spectroscopy of
the three dimensional topological insulator BiSb. The
zero-field results allow us to measure the value of the direct band gap between
the conducting and valence bands. Under applied field in the
Faraday geometry (\emph{k} \emph{H} C1), we measured the presence of
a multitude of Landau level (LL) transitions, all with frequency dependence
. We discuss the ramification of this observation for
the surface and bulk properties of topological insulators.Comment: 7 pages, 8 figures, March Meeting 2011 Abstract: J35.0000
Side-channel-free quantum key distribution
Quantum key distribution (QKD) offers the promise of absolutely secure
communications. However, proofs of absolute security often assume perfect
implementation from theory to experiment. Thus, existing systems may be prone
to insidious side-channel attacks that rely on flaws in experimental
implementation. Here we replace all real channels with virtual channels in a
QKD protocol, making the relevant detectors and settings inside private spaces
inaccessible while simultaneously acting as a Hilbert space filter to eliminate
side-channel attacks. By using a quantum memory we find that we are able to
bound the secret-key rate below by the entanglement-distillation rate computed
over the distributed states.Comment: Considering general quantum systems, we extended QKD to the presence
of an untrusted relay, whose measurement creates secret correlations in
remote stations (achievable rate lower-bounded by the coherent information).
This key ingredient, i.e., the use of a measurement-based untrusted relay,
has been called 'measurement-device independence' in another arXiv submission
(arXiv:1109.1473
Monte Carlo simulation of melting transition on DNA nanocompartment
DNA nanocompartment is a typical DNA-based machine whose function is
dependent of molecular collective effect. Fundamental properties of the device
have been addressed via electrochemical analysis, fluorescent microscopy, and
atomic force microscopy. Interesting and novel phenomena emerged during the
switching of the device. We have found that DNAs in this system exhibit a much
steep melting transition compared to ones in bulk solution or conventional DNA
array. To achieve an understanding to this discrepancy, we introduced DNA-DNA
interaction potential to the conventional Ising-like Zimm-Bragg theory and
Peyrard-Bishop model of DNA melting. To avoid unrealistic numerical calculation
caused by modification of the Peyrard-Bishop nonlinear Hamiltonian with the
DNA-DNA interaction, we established coarse-gained Monte Carlo recursion
relations by elucidation of five components of energy change during melting
transition. The result suggests that DNA-DNA interaction potential accounts for
the observed steep transition.Comment: 12 pages, 5 figure
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