News

[Kunook Chung, Keundong Lee, ,Prof. Gyu-Chul] GaN microstructure light-emitting diodes directly fabr... May 1, 2019 l Hit 1611

We report on the selective-area growth of GaN microstructures on tungsten (W)-metal electrodes using a micro-patterned graphene intermediate layer between GaN and W, and demonstrate their use as light-emitting diodes (LEDs). Prior to the GaN growths, the cm-scale graphene layer was transferred on W and then further pat...

[C. Han/Prof. H. Jeon] Lasing at topological edge states in a photonic crystal L3 nanocavity dimer a... May 1, 2019 l Hit 2099

Topological photonics have provided new insights for the manipulation of light. Analogous to electrons in topological insulators, photons travelling through the surface of a topological photonic structure or the interface of two photonic structures with different topological phases are free from backscattering caused b...

[Junyeong Ahn/Sungjoon Park, Prof. Bohm-Jung Yang] Failure of Nielsen-Ninomiya Theorem and Fragile T... Apr 24, 2019 l Hit 686

We show that the Wannier obstruction and the fragile topology of the nearly flat bands in twisted bilayer graphene at magic angle are manifestations of the nontrivial topology of two-dimensional real wave functions characterized by the Euler class. To prove this, we examine the generic band topology of two dimensional ...

[Dr. Keehoon Kang / Heebeom Ahn / Prof. Takhee Lee] High-Performance Solution-Processed Organo-Halid... Apr 16, 2019 l Hit 1483

Resistive random access memories can potentially open a niche area in memory technology applications by combining the advantages of a long endurance of dynamic random-access memory and a long retention time of flash memories. Recently, resistive memory devices based on organo-halide perovskite materials have demonstrat...

[Micro&Nano Opto-Electronics Lab/ Prof. Heonsu Jeon, Myungjae Lee] Taming of random lasers (Nature P... Apr 11, 2019 l Hit 1715

Taming of random lasers / Random lasers are fascinating devices due to the absence of a conventional cavity structure and their counterintuitive lasing mechanism. However, they are also notorious for their unpredictability. Despite their many unusual properties, random lasers are unlikely to achieve the ubiquito...

[D. Ahn, Dr. Y. S. Teo, Prof. H. Jeong] Adaptive Compressive Tomography with No a priori Information Mar 21, 2019 l Hit 816

Quantum state tomography is both a crucial component in the field of quantum information and computation and a formidable task that requires an incogitable number of measurement configurations as the system dimension grows. We propose and experimentally carry out an intuitive adaptive compressive tomography scheme, ins...

[mnelab / Dr. Seungjun Chung, Dr. Kyungjune, Prof. Takhee Lee] Recent Progress in Inkjet‐Printed Thi... Mar 21, 2019 l Hit 1587

Drop-on-demand inkjet printing is one of the most attractive techniques from a manufacturing perspective due to the possibility of fabrication from a digital layout at ambient conditions, thus leading to great opportunities for the realization of low-cost and flexible thin-film devices. Over the past decades, a variety...

[Jiho Jang, Dr. Seongjin Ahn, Prof. Hongki Min] Optical conductivity of black phosphorus with a tuna... Mar 19, 2019 l Hit 938

Black phosphorus (BP) is a two-dimensional layered material composed of phosphorus atoms. Recently, it was demonstrated that external perturbations such as an electric field close the band gap in few-layer BP, and can even induce a band inversion, resulting in an insulator phase with a finite energy gap or a Dirac semi...

[Quantum Gas Lab.] Observation of Wall-Vortex Composite Defects in a Spinor Bose-Einstein Condensate... Mar 11, 2019 l Hit 1556

We report the observation of spin domain walls bounded by half-quantum vortices (HQVs) in a spin-1 Bose-Einstein condensate with antiferromagnetic interactions. A spinor condensate is initially prepared in the easy-plane polar phase, and then, suddenly quenched into the easy-axis polar phase. Domain walls are created v...