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Related papers: Drifting Abnormal Rolls in Electroconvection of Hy…

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We present the first quantitative verification of an amplitude description for systems with (nearly) spontaneously broken isotropy, in particular for the recently discovered abnormal-roll states. We also obtain a conclusive picture of the…

patt-sol · Physics 2009-10-31 Axel G. Rossberg , Nandor Eber , Agnes Buka , Lorenz Kramer

We report experimental and theoretical results on the flexoelectric instability and crossover between flexoelectric domains and electroconvection in a hybrid aligned nematic MBBA under d.c. voltage. At threshold a spatially periodic…

Pattern Formation and Solitons · Physics 2007-05-23 V. A. Delev , A. P. Krekhov , L. Kramer

We report a liquid-crystal pattern-formation experiment in which we break the lateral (translational) symmetry of a nematic medium with a laser-induced thermal gradient. The work is motivated by an improved measurement (reported here) of…

Soft Condensed Matter · Physics 2009-11-11 Daniel R. Spiegel , Elliot R. Johnson , Skyler R. Saucedo

By employing a local two-fluid theory, we investigate an obliquely propagating electromagnetic instability in the lower hybrid frequency range driven by cross-field current or relative drifts between electrons and ions. The theory…

Astrophysics · Physics 2007-05-23 Hantao Ji , Russell Kulsrud , William Fox , Masaaki Yamada

We investigate a number of complex patterns driven by the electro-convection instability in a planarly aligned layer of a nematic liquid crystal. They are traced back to various secondary instabilities of the ideal roll patterns bifurcating…

Soft Condensed Matter · Physics 2015-12-23 Alexei Krekhov , Bernd Dressel , Werner Pesch , Vladimir Delev , Eduard Batyrshin

A study of secondary instabilities in ac-driven electroconvection of a planarly aligned nematic liquid crystal is presented. At low frequencies one has a transition from normal rolls to a zig-zag pattern and at high frequencies a direct…

patt-sol · Physics 2009-10-31 S. Rudroff , H. Zhao , L. Kramer , I. Rehberg

Novel behavior in electroconvection (EC) has been detected in nematic liquid crystals (NLCs) under the condition of comparable timescales of the director relaxation and the period of the driving ac voltage. The studied NLCs exhibit standard…

Soft Condensed Matter · Physics 2009-11-13 Tibor Toth-Katona , Nandor Eber , Agnes Buka , Alexei Krekhov

Motivated by experiments in electroconvection in nematic liquid crystals with homeotropic alignment we study the coupled amplitude equations describing the formation of a stationary roll pattern in the presence of a weakly-damped mode that…

Pattern Formation and Solitons · Physics 2009-11-07 S. Komineas , H. Zhao , L. Kramer

Pattern forming instabilities induced by ultralow frequency sinusoidal voltages were studied in a rod-like nematic liquid crystal by microscopic observations and simultaneous electric current measurements. Two pattern morphologies,…

Soft Condensed Matter · Physics 2014-09-04 Peter Salamon , Nandor Eber , Alexei Krekhov , Agnes Buka

A new type of instability - electrokinetic instability - and an unusual transition to chaotic motion near a charge-selective surface was studied by numerical integration of the Nernst-Planck-Poisson-Stokes system and a weakly nonlinear…

Fluid Dynamics · Physics 2014-02-17 E. A. Demekhin , N. V. Nikitin , V. S. Shelistov

We report on-off intermittency in electroconvection of nematic liquid crystals driven by a dichotomous stochastic electric voltage. With increasing voltage amplitude we observe laminar phases of undistorted director state interrupted by…

patt-sol · Physics 2009-10-31 Thomas John , Ralf Stannarius , Ulrich Behn

I report on the effects of a periodic modulation of the control parameter on electroconvection in the nematic liquid crystal I52. Without modulation, the primary bifurcation from the uniform state is a direct transition to a state of…

Pattern Formation and Solitons · Physics 2009-10-31 Michael Dennin

We report the motion of individual magnetic Quincke rollers composed of silica particles doped with superparamagnetic iron oxide nanoparticles, whose activity arises from the coupling between Quincke rolling and an externally applied…

Soft Condensed Matter · Physics 2026-04-14 Zoran M. Cenev , Ville S. I. Havu , Jaakko V. I. Timonen

In this experiment a steady state current is maintained through a liquid crystal thin film. When the applied voltage is increased through a threshold, a phase transition is observed into a convective state characterized by the chaotic…

Chaotic Dynamics · Physics 2009-11-07 Walter I. Goldburg , Yadin Y. Goldschmidt , Hamid Kellay

The common description of the electrical behavior of a nematic liquid crystal as an anisotropic dielectric medium with (weak) ohmic conductivity is extended to an electrodiffusion model with two active ionic species. Under appropriate, but…

patt-sol · Physics 2008-02-03 Martin Treiber , Lorenz Kramer

We address the enhancement of electron drift in semiconductor superlattices of nanometre scale that occurs in combined electric and tilted magnetic fields if Bloch oscillations become resonant with cyclotron rotation in the transverse…

Mesoscale and Nanoscale Physics · Physics 2015-05-20 S. M. Soskin , I. A. Khovanov , P. V. E. McClintock

For the first time the electrohydrodynamic convection (EHC) of nematic liquid crystals is studied via fully nonlinear simulation. As a system of rich pattern-formation the EHC is mostly studied with negative nematic liquid crystals…

Soft Condensed Matter · Physics 2016-12-28 Kuang-Wu Lee , Thorsten Pöschel

Magnetic nozzles are a key component of electrodeless plasma thrusters, acting as their main acceleration stage. Non-stationary phenomena common to the entire range of $E \times B$ devices, such as oscillations and instabilities, are likely…

Plasma Physics · Physics 2024-12-16 Matteo Ripoli , Eduardo Ahedo , Mario Merino

The nematic electronic state and its associated nematic critical fluctuations have emerged as potential candidates for superconducting pairing in various unconventional superconductors. However, in most materials their coexistence with…

Superconductivity · Physics 2019-11-19 P. Reiss , D. Graf , A. A. Haghighirad , W. Knafo , L. Drigo , M. Bristow , A. J. Schofield , A. I. Coldea

We investigate the effect of external horizontal magnetic field applied on the convection rolls obliquely (at an angle $\phi$ with the $x$-axis) in electrically conducting low Prandtl number fluids under the paradigm of the…

Fluid Dynamics · Physics 2025-03-18 Snehashish Sarkar , Sutapa Mandal , Pinaki Pal
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