30 research outputs found
Temperature-dependent magnetospectroscopy of HgTe quantum wells
We report on magnetospectroscopy of HgTe quantum wells in magnetic fields up
to 45 T in temperature range from 4.2 K up to 185 K. We observe intra- and
inter-band transitions from zero-mode Landau levels, which split from the
bottom conduction and upper valence subbands, and merge under the applied
magnetic field. To describe experimental results, realistic
temperature-dependent calculations of Landau levels have been performed. We
show that although our samples are topological insulators at low temperatures
only, the signature of such phase persists in optical transitions at high
temperatures and high magnetic fields. Our results demonstrate that
temperature-dependent magnetospectroscopy is a powerful tool to discriminate
trivial and topological insulator phases in HgTe quantum wells
Electrophysical properties of water and ice under isentropic compression to megabar pressures
The ground-state energy of the B-B′-U Hubbard model in the static-fluctuation approximation
Field-Induced Transition in (Nd,Dy)<sub>2</sub>Fe<sub>14</sub>B in Ultrahigh Magnetic Fields
We demonstrate the peculiarities of the magnetization process in the ferrimagnetic intermetallic compound (Nd0.5Dy0.5)2Fe14B, which has been studied theoretically and experimentally using ultrahigh magnetic fields. We observe phase transition induced by external ultrahigh magnetic fields (up to 170 T) and also describe the magnetization process analytically in terms of critical transition fields. In this work, the first and second critical fields of the field-induced magnetic transitions, Hc1 and Hc2, were estimated, and the results were verified against experimental data for Hc1. Critical field Hc2 predicting the place of transition to the forced-ferromagnetic state was estimated for the first time for (Nd0.5Dy0.5)2Fe14B compound. A comparison of the magnetization behavior for (Nd0.5Dy0.5)2Fe14B with the basic systems Nd2Fe14B and Dy2Fe14B is also performed. We demonstrate that, in the Dy2Fe14B compound, the field-induced transition type is changed from the first to the second order due to the replacement of the Nd atom by Dy one