Researchers at Linköping University in Sweden, Shenzhen University and several other universities in China have recently fabricated an efficient diode capable of both emitting and detecting light. [21] Yu-Hwa Lo and colleagues at the University of California in San Diego (UCSD) now report on systematic investigations of how these devices respond to light for frequencies varying over eight orders of magnitude and power ranging from millions to single photons. [20] A new joint Tel Aviv University (TAU) and Karlsruhe Institute of Technology (KIT) study published in Nature Communications on February 28 demonstrates remarkable continuous lasing action in devices made from perovskites. [19] Efficient near-infrared (NIR) light-emitting diodes of perovskite have been produced in a laboratory at Linköping University. The external quantum efficiency is 21.6 percent, which is a record. The results have been published in Nature Photonics. [18] Very recently, an NTU team lead by Assoc. Prof. Wang Hong, demonstrated high light extraction efficiency of perovskite photonic crystals fabricated by delicate electron-beam lithography. [17] A quasiparticle is a disturbance or excitation (e.g. spin waves, bubbles, etc.) that behaves as a particle and could therefore be regarded as one. Long-range interactions between quasiparticles can give rise to a 'drag,' which affects the fundamental properties of many systems in condensed matter physics. [16] Researchers have recently been also interested in the utilization of antiferromagnets, which are materials without macroscopic magnetization but with a staggered orientation of their microscopic magnetic moments. [15] A new method that precisely measures the mysterious behavior and magnetic properties of electrons flowing across the surface of quantum materials could open a path to next-generation electronics. [14] The emerging field of spintronics aims to exploit the spin of the electron. [13] In a new study, researchers measure the spin properties of electronic states produced in singlet fission-a process which could have a central role in the future development of solar cells. [12]