Exotic material exhibits an optical response in enormous disproportion to the stimulus
No earlier theory had envisioned that the responses would be so large! Scientists “poked” three crystals with pulses of light. Unexpectedly, the crystals exhibited the largest nonlinear optical response of any known crystal. The response was a huge amount of different colored light with twice the frequency of the pulse. These crystals are members of a new class of materials known as Weyl semimetals.
This work challenges our thinking on optical responses in Weyl semimetals. We expected light pulses to produce different colored light with twice the frequency but not such a huge response. The origin of this gigantic response is unknown! This study is already stimulating the development of fundamentally new theories about these responses. These materials are promising for package-penetrating sensors, night vision goggles, and other devices.
Weyl fermions are novel particles that were predicted to be seen in high-energy physics experiments but have not been observed. However, scientists recently observed these particles as an emergent property of electrons in a unique set of semimetal materials. Recent studies have shown that Weyl semimetals exhibit an unexpectedly large nonlinear optical response. This response gives rise to the largest optical second harmonic generation effect of any known crystal. These observations were made in the transition metal systems: tantalum arsenide (TaAs), tantalum phosphide (TaP), and niobium arsenide (NbAs).
Archive link
Комментариев нет:
Отправить комментарий