Unfolding and extraction of a transmembrane alpha-?helical peptide: Dynamic Force Spectroscopy and Molecular Dynamics Simulations
Biophysical Journal 89 (2005) 3129-3140
Competing phases in the superconducting state of La2-xSrxCuO4: Temperature- and magnetic-field-dependent quasiparticle relaxation measurements
Physical Review B - Condensed Matter and Materials Physics 72:9 (2005)
Abstract:
We present femtosecond time-resolved measurements of the quasiparticle dynamics in La2-xSrxCuO4 (LSCO) as a function of the temperature and applied magnetic field. Temperature-dependent data correlate with independent equilibrium measurements of superfluid density and charge dynamics. At low temperature, the induced reflectivity transient is established in a two-step process. We propose that this behavior results from the coexistence of two energy scales in the superconducting state of LSCO: the superconducting (SC) gap and a partial gap at higher energy that decrease with increasing doping and vanish in overdoped material. Measurements under applied magnetic field indicate that, in the SC state, the response is remarkably sensitive to a c-axis field. We show that this is due to the development of nonsuperconducting regions of size ∼130 surrounding vortex cores. The data show that a partial gap persists in these regions, suggesting that this gap is associated with electronic correlations competing with superconductivity. © 2005 The American Physical Society.Characterization of beta-amyloid(1-40) incorporated in model membranes: peptide conformation, acyl chain order, vesicle morphology, supported bilayer topography, and channel activity
FEBS J 272 (2005) 235-236
(110) InAs quantum dots: Growth, single-dot luminescence and cleaved edge alignment
Materials Research Society Symposium Proceedings 829 (2005) 21-32
Abstract:
The formation of InAs self-assembled quantum dots on (110) GaAs substrates is demonstrated. These dots form with significantly lower densities than InAs dots grown on (100) GaAs. The low density growth mode of these InAs nanostructures allows for the fabrication of devices capable of electroluminescence from individual quantum dots. Such a device has been fabricated with conventional photolithography and its emission spectra characterized. Additionally, because GaAs cleaves naturally along the (110) crystal plane, the ability to grow InAs quantum dots on (110) GaAs substrates allows for the growth of these dots on the cleaved edges of GaAs first growth samples containing InGaAs strain layers of varying thickness and In fraction. 100% linear alignment of InAs quantum dots over these InGaAs strain layers is demonstrated. © 2005 Materials Research Society.Nonequilibrium quasiparticle relaxation in the vortex state of La2-xSrxCuO4
Physical Review Letters 94 (2005) 107004 4pp