Influence of neutron irradiation on the electronic properties of hexagonal boron nitride measured by terahertz time-domain spectroscopy.

Due to the low atomic number of B, hexagonal boron nitride (hBN) has a large neutron scattering cross section and, therefore, is an ideal material for the realization of solid-state neutron detector. Here we apply the THz time-domain spectroscopy to study the effect of neutron irradiation on electronic properties of pyrolytic (PBN) and hot-pressed boron nitride (HBN). The key electronic parameters of these samples, such as the static dielectric constant , the effective carrier density N*, the carrier relaxation time τ, and the electronic localization factor α, are determined optically, and their dependences upon the neutron irradiation fluence (NIF) are examined.

Turning single bubble sonoluminescence from blue in pure water to green by adding trace amount of carbon nanodots.

Sonoluminescence (SL) is an interesting physical effect which can convert acoustic energy into light pulses. Up to now, the microscopic mechanism of the SL has not yet been fully clear. It is known that hydroxyl radicals play the important role for SL from water.

Influence of carbon nano-dots in water on sonoluminescence.

Sonoluminescence (SL) occurs when acoustically induced oscillating bubbles in a liquid collapse. The SL from pure water normally generates ultraviolet to blue emission which is related to hydroxyl plasma formed in and around the bubbles. It is known that carbon nano-dots (CNDs) can serve as free radical captors, where the C-bonds can couple strongly with free radicals and form C-based functional groups.

Terahertz optical Hall effect in p-type monolayer hexagonal boron nitride on fused silica substrate.

We demonstrate for the first time, to the best of our knowledge, that the optical Hall effect (OHE) can be observed in p-type monolayer (ML) hexagonal boron nitride (hBN) on a fused silica substrate by applying linearly polarized terahertz (THz) irradiation. When ML hBN is placed on fused silica, in which the incident pulsed THz field can create local and transient electromagnetic dipoles, proximity-induced interactions can be presented. The Rashba spin-orbit coupling can be enhanced, and the in-plane spin component can be induced, along with the lifting of valley degeneracy.