58,719 research outputs found
Specific Heat of Disordered He
Porous aerogel is a source of elastic scattering in superfluid 3He and
modifies the properties of the superfluid, suppressing the transition
temperature and order parameter. The specific heat jumps for the B-phase of
superfluid 3He in aerogel have been measured as a function of pressure and
interpreted using the homogeneous and inhomogeneous isotropic scattering
models. The specific heat jumps for other p-wave states are estimated for
comparison.Comment: Manuscript prepared for LT 2
The benefits of in silico modeling to identify possible small-molecule drugs and their off-target interactions
Accepted for publication in a future issue of Future Medicinal Chemistry.The research into the use of small molecules as drugs continues to be a key driver in the development of molecular databases, computer-aided drug design software and collaborative platforms. The evolution of computational approaches is driven by the essential criteria that a drug molecule has to fulfill, from the affinity to targets to minimal side effects while having adequate absorption, distribution, metabolism, and excretion (ADME) properties. A combination of ligand- and structure-based drug development approaches is already used to obtain consensus predictions of small molecule activities and their off-target interactions. Further integration of these methods into easy-to-use workflows informed by systems biology could realize the full potential of available data in the drug discovery and reduce the attrition of drug candidates.Peer reviewe
Kondo resonance of a Co atom exchange coupled to a ferromagnetic tip
The Kondo effect of a Co atom on Cu(100) was investigated with a
low-temperature scanning tunneling microscope using a monoatomically sharp
nickel tip. Upon a tip-Co contact, the differential conductance spectra exhibit
a spin-split asymmetric Kondo resonance. The computed ab initio value of the
exchange coupling is too small to suppress the Kondo effect, but sufficiently
large to produce the splitting observed. A quantitative analysis of the line
shape using the numerical renormalization group technique indicates that the
junction spin polarization is weak.Comment: 5 pages, 4 figure
Signature of high temperature superconductivity in electron doped Sr2IrO4
Sr2IrO4 was predicted to be a high temperature superconductor upon electron
doping since it highly resembles the cuprates in crystal structure, electronic
structure and magnetic coupling constants. Here we report a scanning tunneling
microscopy/spectroscopy (STM/STS) study of Sr2IrO4 with surface electron doping
by depositing potassium (K) atoms. At the 0.5-0.7 monolayer (ML) K coverage, we
observed a sharp, V-shaped gap with about 95% loss of density of state (DOS) at
EFand visible coherence peaks. The gap magnitude is 25-30 meV for 0.5-0.6 ML K
coverage and it closes around 50 K. These behaviors exhibit clear signature of
superconductivity. Furthermore, we found that with increased electron doping,
the system gradually evolves from an insulating state to a normal metallic
state, via a pseudogap-like state and possible superconducting state. Our data
suggest possible high temperature superconductivity in electron doped Sr2IrO4,
and its remarkable analogy to the cuprates.Comment: 11 pages, 5 figure
Measuring Which-Path Information with Coupled Electronic Mach-Zehnder Interferometers
We theoretically investigate a generalized "which-path" measurement on an
electronic Mach-Zehnder Interferometer (MZI) implemented via Coulomb coupling
to a second electronic MZI acting as a detector. The use of contextual values,
or generalized eigenvalues, enables the precise construction of which-path
operator averages that are valid for any measurement strength from the
available drain currents. The form of the contextual values provides direct
physical insight about the measurement being performed, providing information
about the correlation strength between system and detector, the measurement
inefficiency, and the proper background removal. We find that the detector
interferometer must display maximal wave-like behavior to optimally measure the
particle-like which-path information in the system interferometer,
demonstrating wave-particle complementarity between the system and detector. We
also find that the degree of quantum erasure that can be achieved by
conditioning on a specific detector drain is directly related to the ambiguity
of the measurement. Finally, conditioning the which-path averages on a
particular system drain using the zero frequency cross-correlations produces
conditioned averages that can become anomalously large due to quantum
interference; the weak coupling limit of these conditioned averages can produce
both weak values and detector-dependent semi-weak values.Comment: 17 pages, 12 figures, published version including appendi
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