Adiabatic control is one of the promising techniques for manipulating quantum systems. It, however, requires an infinitely slow operation and is of limited use for practical applications. “Shortcuts to adiabaticity” is a series of methods to mimic adiabatic time evolution within a shorter time. We review the recent progress of shortcuts to adiabaticity and discuss universal aspects of dynamics.
Discovery of very high energy gamma-ray emission from GRB 190114C by MAGIC telescopes is reported briefly, together with episodes around it, which are not seen in the papers. The energy of the detected gamma-rays reached at 1 TeV for the first time, and the detection continued up to about one hour after the onset of the burst. It opens a new era of GRB physics with imaging atmospheric Cherenkov telescopes such as Cherenkov Telescope Array.
We investigate a simple forced harmonic oscillator with a natural frequency varying with time. It is shown that the time evolution of such a system can be written in a simplified form with Fresnel integrals, as long as the variation of the natural frequency is very slow compared to the oscillation period. As a result, we found that a forced harmonic oscillator with a slowly-varying natural frequency is essentially equivalent to diffraction of light.
Spin-triplet superconductivity due to Cooper pairs with spin 1 degree of freedom has been increasingly attracted interest as a candidate for topological superconducting materials. A spin-triplet superconducting state is expected to emerge in the vicinity of the ferromagnetic phase, as found in Uranium-based heavy-fermion systems. Using first-principles calculations and extending Fermi surface formulas, we theoretically predict topological superconductivity in UCoGe and a newly discovered superconductor UTe2 .
A miniature cubic-anvil pressure cell having an outer diameter of 60 mm, the smallest cubic-anvil cell to date, was fabricated to insert in a large-bore superconducting magnet. The pressure cell has a sample space of ϕ2.5×1.5 mm, which is fairly large for a pressure cell that can reach a high pressure above 4 GPa. Pressure homogeneity was monitored from the 63Cu nuclear-quadrupole-resonance linewidth of Cu2O up to 6.7 GPa. The linewidth first increased with increasing pressure up to 4 GPa and then saturated above 4 GPa. The pressure homogeneity was better than that of a piston–cylinder pressure cell. This newly developed pressure cell is advantageous because a large sample space and high pressure homogeneity are secured even at high pressures.