2,222 research outputs found
On the energetics of information exchange
We consider the thermodynamic properties of systems in contact with an
information source and focus on the consequences of energetic cost associated
with the exchange of information. To this end we introduce the model of a
thermal tape and derive a general bound for the efficiency of work extraction
for systems in contact with such a tape. Depending on the perspective, the
correlations between system and tape may either increase or reduce the
efficiency of the device. We illustrate our general results with two exactly
solvable models, one being an autonomous system, the other one involving
measurement and feedback. We also define an ideal tape limit in which our
findings reduce to known results.Comment: 6 pages, 6 figure
Detection of Single Spin Decoherence in a Quantum Dot via Charge Currents
We consider a quantum dot attached to leads in the Coulomb blockade regime
which has a spin 1/2 ground state. We show that by applying an ESR field to the
dot-spin the stationary current in the sequential tunneling regime exhibits a
resonance whose line width is determined by the single-spin decoherence time
T_2. The Rabi oscillations of the dot-spin are shown to induce coherent current
oscillations from which T_2 can be deduced in the time domain. We describe a
spin-inverter which can be used to pump current through a double-dot via spin
flips generated by ESR.Comment: 4 pages, 3 figure
Detection Mechanism in SNSPD: Numerical Results of a Conceptually Simple, Yet Powerful Detection Model
In a recent publication we have proposed a numerical model that describes the
detection process of optical photons in superconducting nanowire single-photon
detectors (SNSPD). Here, we review this model and present a significant
improvement that allows us to calculate more accurate current distributions for
the inhomogeneous quasi-particle densities occurring after photon absorption.
With this new algorithm we explore the detector response in standard NbN SNSPD
for photons absorbed off-center and for 2-photon processes. We also discuss the
outstanding performance of SNSPD based on WSi. Our numerical results indicate a
different detection mechanism in WSi than in NbN or similar materials.Comment: Presented at ASC 2014 (invited) and submitted to IEEE Transaction on
Applied Superconductivity (Special Issue
Role Induced Bias in Court: An Experimental Analysis
Criminal procedure is organized as a tournament with predefined roles. We show that assuming the role of a defense counsel or prosecutor leads to role induced bias even if participants are asked to predict a court ruling after they have ceased to act in that role, and if they expect a substantial financial incentive for being accurate. The bias is not removed either if participants are instructed to predict the court ruling in preparation of plea bargaining. In line with parallel constraint satisfaction models for legal decision making, findings indicate that role induced bias is driven by coherence effects (Simon, 2004), that is, systematic information distortions in support of the favored option. This is mainly achieved by downplaying the importance of conflicting evidence. These distortions seem to stabilize interpretations, and people do not correct for this bias. Implications for legal procedure are briefly discussed.Coherence effects, Legal Decision Making, Biases, Parallel Constraint Satisfaction, Intuition
Does R&D-infrastructure attract high-tech start-ups?
Our research, based on the ZEW-Foundation Panel East, examines whether high-tech start-ups are mainly founded in scientific and infrastructural well suited regions or not. Estimation results on the level of postcode areas confirm the hypothesis that specific human capital, knowledge spillovers at higher-education institutions are more important for founding a firm in one of the high-tech sectors compared with the effects of other publicly financed institutions. The existence of large companies in the manufacturing sector has a considerable effect for start-up activities in this region in general. Moreover, high-tech start-ups are more concentrated within or near technology and foundation centres. --High Technology Industries,Eastern Germany,Start-ups,entrepreneurs
The Dilworth Number of Auto-Chordal-Bipartite Graphs
The mirror (or bipartite complement) mir(B) of a bipartite graph B=(X,Y,E)
has the same color classes X and Y as B, and two vertices x in X and y in Y are
adjacent in mir(B) if and only if xy is not in E. A bipartite graph is chordal
bipartite if none of its induced subgraphs is a chordless cycle with at least
six vertices. In this paper, we deal with chordal bipartite graphs whose mirror
is chordal bipartite as well; we call these graphs auto-chordal bipartite
graphs (ACB graphs for short). We describe the relationship to some known graph
classes such as interval and strongly chordal graphs and we present several
characterizations of ACB graphs. We show that ACB graphs have unbounded
Dilworth number, and we characterize ACB graphs with Dilworth number k
Influence of surface tension on the conical miniscus of a magnetic fluid in the field of a current-carrying wire
We study the influence of surface tension on the shape of the conical
miniscus built up by a magnetic fluid surrounding a current-carrying wire.
Minimization of the total energy of the system leads to a singular second order
boundary value problem for the function describing the axially
symmetric shape of the free surface. An appropriate transformation regularizes
the problem and allows a straightforward numerical solution. We also study the
effects a superimposed second liquid, a nonlinear magnetization law of the
magnetic fluid, and the influence of the diameter of the wire on the free
surface profile
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