RIKEN Center for Emergent Matter Science

Largely Negative Energy Difference between the Singlet and Triplet Excited States and Ultrafast Delayed Fluorescence

Abstract Molecules exhibiting inversion of the lowest singlet and triplet excited states, referred to as inverted singlet–triplet (IST) molecules, can show a short delayed lifetime below 1 μs and are therefore promising candidates for next-generation emitters in organic light-emi...

Bulky‐Group‐Functionalized Bidentate Pt(II) Complexes With Aggregation‐Induced Emission for Blue Phosphorescent Organic Light‐Emitting Diodes

Pt(II) metal complexes with aggregation‐induced emission (AIE) properties are creating new opportunities in the fields of optoelectronics and their applications. We synthesized a series of AIE‐active sky blue and bluish green Pt(II) complexes with varying structures, such as (Pt1...

Pressure-Gated Ionic Contact in Multilayered Nanomeshes Enables Strain-Insensitive Pressure Sensing

Abstract Soft robotic grippers require tactile interfaces that selectively detect contact pressure at the object–gripper interface without strain-induced artifacts from gripper deformation. Here, we report an ultrathin pressure-gated ionic-contact (PGIC) sensor for multidirection...

First-Principles Calculations of the Magnetocrystalline Anisotropy Energy in Disordered Alloys Using Wannier-based Coherent Potential Approximation

We present a method for calculating the magnetocrystalline anisotropy energy (MAE) of disordered alloys using Green’s functions constructed from Wannier Hamiltonians within the coherent potential approximation (Wannier-CPA). The MAE of a disordered alloy system is obtained from t...

Indication of stochastic photothermal dynamics around a topological defect in a chiral magnet

Chiral magnets host topologically protected spin textures whose nonequilibrium dynamics are crucial in phase transitions and domain evolution, yet ultrafast defect-mediated processes remain poorly understood. Here, we investigate a photothermally induced helical-to-paramagnetic p...

Nonmonotonic scaling of the anomalous Hall effect in a bicollinear antiferromagnet

An anomalous Hall effect (AHE) in antiferromagnetic (AF) systems without net magnetization is of considerable interest for fundamental physics and spintronic applications. Of particular interest is the two-dimensional van der Waals antiferromagnet iron telluride (FeTe), which has...

Shear‐Mode Direct Piezoelectric Response of Ferroelectric Nematic Liquid Crystals

ABSTRACT Piezoelectricity (linear coupling between mechanical deformation and electric signal) was originally observed only in solid crystals. Recently, it was discovered that liquid ferroelectric nematic liquid crystals are also piezoelectric. However, so far only their converse...

Berry curvature dipole generation and nonreciprocal spin photocurrents in ferroelectricity polarized heterostructures

Berry curvature dipole (BCD) describes the dipole-like distribution of Berry curvature in momentum space and plays a key role for quantum geometric phenomena in nonlinear optoelectronics. Experimentally, BCD can be generated at artificially designed semiconductor heterointerfaces...

Helical-to-Fan Transitions under Magnetic Fields in the Noncentrosymmetric Tetragonal Magnet EuRhGe 3

The magnetic structure of EuRhGe 3 , a noncentrosymmetric body-centered tetragonal magnet with the space group I4mm, has been investigated by resonant X-ray diffraction. Below T N = 12 K, EuRhGe 3 undergoes a helical magnetic ordering with an incommensurate propagation vector [Fo...

Prominent Intrinsic Orbital Hall Effect in the 135 Kagome Metal Family and Orbital Responses in the Loop-Current Phase

The study of electronic orbital degrees of freedom, including the generation and control of orbital currents and orbital angular momentum, has emerged as a vibrant research field. Here, we study the orbital Hall effect (OHE), one of the key mechanisms for orbital current generati...

Recent advances in flexible near infrared—short wave infrared image sensors: from materials to applications

Near-infrared and short-wave infrared (NIR–SWIR) light reveals molecular signatures and penetrates scattering media, advantages that are greatest in direct contact with target. Rigid, conventional imagers cannot meet this requirement. Flexible imagers, by contrast, conform to ski...