Yuval Lamhot

Local characterization of superconductivity inBaFe2(As1−xPx)2

We use magnetic force microscopy (MFM) to characterize superconductivity across the superconducting dome in BaFe2(As1-xPx)2, a pnictide with a peak in the penetration depth ( ab λ ) at optimal doping (xopt), as shown in sample-wide measurements. Our local measurements show a peak at xopt and a C T vs. 2 ab λ − dependence similar on both sides of xopt. Near the underdoped edge of the dome ab λ increases sharply suggesting that superconductivity competes with another phase. Indeed MFM vortex imaging shows correlated defects parallel to twin boundaries only in underdoped samples and not for x ≥ xopt.

Diamagnetic vortex barrier stripes in underdoped BaFe2(As1-xPx)2

We report magnetic force microscopy (MFM) measurements on underdoped

Autoresonant propagation of incoherent light-waves

BaFe_2(As_{1-x}P_x)_2

Complex nonlinear opto-fluidics: Controlling flow with light and vice-versa

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Optical control of surface-tension effects in complex nanofluids

x=0.26

Complex Dynamic Optofluidics: Symbiotic Nonlinear Controls, Self-pulsation, and Chaos

) that show enhanced superconductivity along stripes parallel to twin boundaries. These stripes of enhanced diamagnetic response repel vortices when we cool in a finite magnetic field and act as barriers when we drag vortices with the magnetic MFM tip. The stripes disappear when we warm the sample towards the superconducting transition temperature. We show that stripes can move when we warm the sample and comment on the relationship between the stripes and similar stripes observed previously in

Self-Trapping of Optical Beams through Thermophoresis

Ba(Fe_{1-x}Co_x)_2As_2

Autoresonant Dynamics of Optical Guided Waves

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Optical Control of Thermocapillary Effects in Complex Nanofluids

We study, theoretically and experimentally, the evolution of optical waves with randomly-fluctuating phases in a spatially chirped nonlinear directional coupler. As the system crosses its linear resonance, we observe collective self-phase-locking (autoresonance) of all mutually-incoherent waves, each with its own pump, and simultaneous amplification until the pumps are exhausted. We show that the autoresonant transition in this system exhibits a sharp threshold, common to all mutually-incoherent waves comprising the light beam.

Local characterization of superconductivity in BaFe

We demonstrate symbiotic dynamics of light and nano-particles suspended in liquid. Light-force varies the local particle density, modifies the fluid properties (surface-tension, viscosity), inducing flow patterns in the fluid, causing synergetic nonlinear-dynamics of light and fluid.