Pressure-induced quantum phase transitions in aYbB6single crystal

The first observation of two pressure-induced quantum phase transitions in a YbB${}_{6}$ single crystal is reported. This material is currently of much interest as there is conflicting experimental support for it belonging to a new class of topological insulators. Based on the results here the authors conclude that while at ambient-pressure YbB${}_{6}$ is topologically trivial, a newly found high-pressure gapped phase could be topologically nontrivial, although a partially gapped semimetal state has also been suggested. This interesting phase deserves further investigation.