Guaranteed energy-efficient bit reset in finite time

Landauer's principle states that it costs at least kTln2 of work to reset one bit in the presence of a heat bath at temperature T. The bound of kTln2 is achieved in the unphysical infinite-time limit. Here we ask what is possible if one is restricted to finite-time protocols. We prove analytically that it is possible to reset a bit with a work cost close to kTln2 in a finite time. We construct an explicit protocol that achieves this, which involves changing the system's Hamiltonian avoiding quantum coherences, and thermalising. Using concepts and techniques pertaining to single-shot statistical mechanics, we further develop the limit on the work cost, proving that the heat dissipated is close to the minimal possible not just on average, but guaranteed with high confidence in every run. Moreover we exploit the protocol to design a quantum heat engine that works near the Carnot efficiency in finite time.Comment: 5 pages + 5 page technical appendix. 5 figures. Author accepted versio

Development of a Novel Method for Assessing Balance: the Quantitative Posturography System

Balance is the ability to maintain equilibrium while sitting or standing. There are a number of different methods, which are used to assess balance: technical methods such as Sway Magnetometry, Ataxia Meter and Force Platforms and clinical methods such as Functional Reach Test, Berg Balance Test and Fall Risk Index. The most frequently used technical method is the force platform. There are two types of Force Platform a static and a dynamic Force Platform of which the dynamic Force Platform has been found to be more sensitive at detecting impaired balance. The Quantitative Posturography System (QPS) described in this paper is a type of dynamic Force Platform, however it has a simpler design to the currently available dynamic Force Platforms and can match the subjects sway exactly for tilting in the Anterio-Posterior and Medio-Lateral directions with its novel design. This paper describes the novel design of the QPS and its calibration

Project for the analysis of technology transfer Quarterly report, 13 Jul. - 12 Oct. 1968

Statistical characteristics of transfer data bank users, and outline of technology transfer and utilization instruction cours

Project for the analysis of technology transfer Quarterly evaluation report, 13 Oct. - 12 Dec. 1968

Technical support package usage documentation by technology transfer analysis projec

A study of the Gribov copies in linear covariant gauges in Euclidean Yang-Mills theories

The Gribov copies and their consequences on the infrared behavior of the gluon propagator are investigated in Euclidean Yang-Mills theories quantized in linear covariant gauges. Considering small values of the gauge parameter, it turns out that the transverse component of the gluon propagator is suppressed, while its longitudinal part is left unchanged. A Green function, G_{tr}, which displays infrared enhancement and which reduces to the ghost propagator in the Landau gauge is identified. The inclusion of the dimension two gluon condensate is also considered. In this case, the transverse component of the gluon propagator and the Green function G_{tr} remain suppressed and enhanced, respectively. Moreover, the longitudinal part of the gluon propagator becomes suppressed. A comparison with the results obtained from the studies of the Schwinger-Dyson equations and from lattice simulations is provided.Comment: 20 page

Models for the lens and source of B0218+357 - A LensClean approach to determine H0

B0218+357 is one of the most promising systems to determine the Hubble constant from gravitational lenses. Consisting of two bright resolved images plus an Einstein ring, it provides better constraints for the mass model than other systems. The main problem left until now was the poorly determined position of the lensing galaxy. After presenting results from classical lens modelling, we apply our improved version of LensClean which utilizes the Einstein ring for lens modelling purposes. The primary result using isothermal models is a well defined lens position which allows the first reliable measurement of the Hubble constant from this system. The result of H0=(78+-6) km/s/Mpc (2 sigma) is high compared with other lenses but compatible with the HST key project and WMAP results. We furthermore discuss effects of different radial mass profiles. The power-law exponent of the potential is constrained by VLBI data to be beta=1.04+-0.02, very close to isothermal. The effect on H0 is expected to be very small. We also present a composite map (lensed and unlensed) which shows the rich structure of B0218+357 on scales from milli-arcseconds to arcseconds. Finally we use a comparison of observations at different frequencies to investigate the question of possible weakening of one of the images by propagation effects and/or source shifts with frequency. The data clearly favour the model of significant extinction without noticeable source position shifts. The technical details of our variant of the LensClean method are presented in the accompanying Paper I.Comment: To appear in MNRAS together with Paper I (astro-ph/0312262). 18 Pages. Full resolution version available at http://www.astro.physik.uni-potsdam.de/~olaf or on reques