Direct measurement of quasiparticle-lifetime broadening in a strong-coupled superconductor

We have measured the quasiparticle recombination time in the strong-coupled superconductor Pb0.9Bi0.1 directly by measuring the lifetime-broadened energy gap edge. This is done by measuring the I-V characteristics of a superconducting tunnel junction of the type Pb0.9Bi0.1-insulator-Pb0.9Bi0.1. Agreement with the calculated value is excellent

Measurements of the time-dependent specific heat of amorphous materials

The time dependence of the specific heat of several amorphous materials, such as a-SiO2, a-As2S3, and a-As, has been studied in the temperature range 0.1-1 K. It is found that below 0.3 K in all the materials studied the short-time specific heat at about 10 μsec is considerably smaller than the long-time specific heat, but larger than the Debye value. Above 0.3 K most of the specific heat is coupled to the phonons already at 10 μsec. However, measurements at very long time scales reveal that the specific heat has a component with a logarithmic time dependence, as proposed by the tunneling model, although only part of the total specific heat can be ascribed to it

Observation of a new superconducting state at high quasiparticle injection

The behavior of a superconducting A1 film under conditions of large nonequilibrium injection of quasiparticles is studied by means of a tunnel generator and detector. At a critical injection density, nc, a second energy gap develops in the superconductor. The relevance to recent theories of nonequilibrium superconductivity is discussed

Scanning Probe-Based Lithography for Production of Biological and Organic Nanostructures on Surfaces

© 2011 Elsevier B.V. All rights reserved. This chapter reviews scanning probe lithography in the production of surface- supported organic and biological materials from the perspective of updated products, technical specifications, and potentials. Three methods are described - nanoshaving, nanografting, and nanopen reader and writer - which depend on atomic force microscopy-based nanolithography. The principal steps and resolutions are discussed in conjunction with specific examples of organic and biological nanostructures produced. The advantages and limitations are also summarized. Two techniques based on scanning tunneling microscopy (STM) - electrical field and tunneling electron-induced nanolithography - are also described. The unprecedented resolution of STM-based methods are revealed using the organic nanostructures produced. Finally, future perspectives using scanning probe microscopy-based nanolithography are discussed

PREPARATION OF LOW CONCENTRATION HIGH MOBILITY n AND p-PbTe

Nous donnons le résultat de l'utilisation de certaines techniques de croissance et de recuit pour la préparation du PbTe de types n et p. Il a été possible de préparer du PbTe intrinsèque à la température ordinaire. Des mobilités maximums de 4,7 × 106et 2,8 × 106 cm2 V-1 sec.-1 ont été observées dans les matériaux n et p respectivement.We report the result of some growth and annealing techniques in the preparation of n and p-PbTe. PbTe has been grown which is intrinsic at room temperature. Maximums mobilities of 4.7 × 106 and 2.8 × 106 cm2/V × sec have been observed in n and p materials, respectively

The time dependent specific heat of dielectric glasses

Measurements on the time dependence of the specific heat exist now both at short and long timescales. Below 0.3 K the short time (~10 µs) specific heat of all the materials studied is smaller than the long time specific heat, but larger than the Debye value. Above 0.2 K most of the specific heat is coupled to the phonons already at 10 µs. However, measurements at very long timescales reveal that the specific heat has a component with a logarithmic time dependence, as proposed by the tunneling model, although only part of the total specific heat can be ascribed to it

Fabrication of nanometer-sized protein patterns using atomic force microscopy and selective immobilization.

A new methodology is introduced to produce nanometer-sized protein patterns. The approach includes two main steps, nanopatterning of self-assembled monolayers using atomic force microscopy (AFM)-based nanolithography and subsequent selective immobilization of proteins on the patterned monolayers. The resulting templates and protein patterns are characterized in situ using AFM. Compared with conventional protein fabrication methods, this approach is able to produce smaller patterns with higher spatial precision. In addition, fabrication and characterization are completed in near physiological conditions. The adsorption configuration and bioreactivity of the proteins within the nanopatterns are also studied in situ