212 citations · 514 across the 13 of their papers we have counts for
14 papers
Shear-mode Direct Piezoelectric Response of Ferroelectric Nematic Liquid Crystals
Péter Salamon, Marcell Tibor Máthé, Hiroya Nishikawa +2
Piezoelectricity (linear coupling between mechanical deformation and electric signal) was originally observed only in solid crystals. Recently, it was discovered that liquid ferroe…
Electrically Tunable Heliconical Smectic Superstructure in Polar Fluids
Hiroya Nishikawa, Dennis Kwaria, Atsuko Nihonyanagi +3
The ferroelectric nematic (NF) phase and related polar liquid-crystalline phases form a new class of strongly polarized yet fluid soft matter. Well-recognized heliconical ferroelec…
Three-Dimensional Hieratical Twists in Polar Fluids: Chirality Regulation by Ultra-Low Electric Field
Hiroya Nishikawa, Dennis Kwaria, Atsuko Nihonyanagi +1
Recently discovered helical polar fluid adopts a spontaneous chiral symmetry breaking (CSB) driven by polarization escape and conformational chirality. Ferroelectric nematic and sm…
Spontaneous Twist of Ferroelectric Smectic Blocks in Polar Fluids
Hiroya Nishikawa, Yasushi Okumura, Dennis Kwaria +2
In soft matter, the polar orientational order of molecules can facilitate the coexistence of structural chirality and ferroelectricity. The ferroelectric nematic (NF) state, exhibi…
Giant Electro-Viscous Effects in Polar Fluids with Paraelectric-Modulated Antiferroelectric-Ferroelectric Phase Sequence
Hiroya Nishikawa, Péter Salamon, Marcell Tibor Máthé +2
The recently discovered ferroelectric nematic liquid-crystal material DIO exhibits an antiferroelectric (AF) phase, characterized by a sinusoidally modulated structure between the…
Ferroelectric Smectic C Liquid Crystal Phase with Spontaneous Polarization in the Direction of the Director
Hirotsugu Kikuchi, Hiroya Nishikawa, Hiroyuki Matsukizono +4
In our previous study, we demonstrated the existence of an unidentified ferroelectric smectic phase in the low-temperature region of the ferroelectric smectic A phase, where the la…
Tunable Intracavity Coherent Up-conversion with Giant Nonlinearity in a Polar Fluidic Medium
Daichi Okada, Hiroya Nishikawa, Fumito Araoka
We demonstrate a novel microcavity-based photon up-conversion using second harmonic generation (SHG) from a polar nematic fluid media doped with a laser dye. The present idea is ba…
Emergent Ferroelectric Nematic and Heliconical Ferroelectric Nematic States in an Achiral "Straight" Polar Rod Mesogen
Hiroya Nishikawa, Daichi Okada, Dennis Kwaria +4
Ferroelectric nematic liquid crystals (NFLCs) are distinguished by their remarkable polarization characteristics and diverse physical phenomena, sparking significant interest and e…
Transformation of polar nematic phases in the presence of electric field
A. V. Emelyanenko, V. Yu. Rudyak, F. Araoka +2
Only a few years have passed since discovery of polar nematics, and now they are becoming the most actively studied liquid crystal materials. Despite numerous breakthrough findings…
Nano-Clustering Mediates Phase Transitions in a Diastereomerically-Stabilized Ferroelectric Nematic System
Hiroya Nishikawa, Koki Sano, Saburo Kurihara +4
During the last half-decade, a new class of ferroic-fluid, ferroelectric nematic liquid crystals (NFLCs), creates a noise owing to its exceptional properties such as a colossal pol…
Observation of Spontaneous Helielectric Nematic Fluids: Electric Analogy to Helimagnets
Xiuhu Zhao, Junchen Zhou, Hiroya Nishikawa +5
About a century ago, Born proposed a possible matter of state, ferroelectric fluid, might exist if the dipole moment is strong enough. The experimental realisation of such states n…
Development of polar nematic fluids with giant-\k{appa} dielectric properties
Jinxing Li, Hiroya Nishikawa, Junichi Kougo +7
Super-high-\k{appa} materials that exhibit exceptionally high dielectric permittivity are recognized as potential candidates for a wide range of next-generation photonic and electr…
Accelerated core collapse in tidally stripped self-interacting dark matter halos
Hiroya Nishikawa, Kimberly K. Boddy, Manoj Kaplinghat
We use a semianalytic approach that is calibrated to N-body simulations to study the evolution of self-interacting dark matter cores in galaxies. We demarcate the regime where the…
Primordial-black-hole mergers in dark-matter spikes
Hiroya Nishikawa, Ely D. Kovetz, Marc Kamionkowski +1
It has been suggested that primordial black holes (PBHs) of roughly 30 solar masses could make up the dark matter and if so, might account for the recent detections by LIGO involvi…