Scientists at UCLA, for the first time, experimentally realized a new compound single crystal, boron arsenide (BAs) and explored its thermal conductivity limit when crystals are free of defects. They observed the highest isotropic thermal conductivity, 1300 W/mK, beyond all common metals and semiconductors. This study established a new benchmark thermal materials that could potentially revolutionize thermal management technologies in electronics and photonics. This work is reported in the paper “Experimental Observation of High Thermal Conductivity in Boron Arsenide,” published online this week in Science.