Stanley Steers

Marangoni shocks in unobstructed soap-film flows.

It is widely thought that in steady, gravity-driven, unobstructed soap-film flows, the velocity increases monotonically downstream. Here we show experimentally that the velocity increases, peaks, drops abruptly, then lessens gradually downstream. We argue theoretically and verify experimentally that the abrupt drop in velocity corresponds to a Marangoni shock, a type of shock related to the elasticity of the film. Marangoni shocks induce locally intense turbulent fluctuations and may help elucidate the mechanisms that produce two-dimensional turbulence away from boundaries.

Direct measurement of turbulent shear

Abstract A photon correlation method is introduced for measuring components of the shear rate tensor in a turbulent soap film. This new scheme, which is also applicable to three-dimensional flows, is shown to give the same results as laser Doppler velocimetry, but with less statistical noise. The technique yields the mean shear rate s ¯ , its standard deviation σ , and a simple mathematical transform of the probability density function P ( s ) of the shear rate itself.

Doping-dependent critical Cooper-pair momentum

We apply a low-field (

p_{c}

l100

in thin underdoped cuprate films

G) technique to measure the critical pair momentum

Evidence for a π junction in Nb / Ni 0.96 V 0.04 / Nb trilayers revealed by superfluid density measurements

{p}_{c}

Evidence for a New State in Films of Underdoped Cuprate Superconductors

in thin underdoped films of

Investigating Simultaneous Suppression of Superfluid and Resistivity in Ultrathin, Severely Underdoped YBCO

{\mathrm{Y}}_{0.7}{\mathrm{Ca}}_{0.3}{\mathrm{Ba}}_{2}{\mathrm{Cu}}_{3}{\mathrm{O}}_{7\ensuremath{-}\ensuremath{\delta}}

Simultaneous suppression of superfluid and resistance on approach to superconductor-insulator transition in underdoped ultrathin Ca 0.3 Y 0.7 Ba 2 Cu 3 O 7 − δ films

and

Investigating Links Between Enhanced Inhomogeneity and Robustness of the Superconducting State in Severely Underdoped, Ultrathin CaYBCO

{\mathrm{Bi}}_{2}{\mathrm{Sr}}_{2}{\mathrm{CaCu}}_{2}{\mathrm{O}}_{8+\ensuremath{\delta}}