Comment on “Investigation on Anomalous Thermal Quenching of Mn4+ Luminescence in A2XF6:Mn4+” [ECS J. Solid State Sci. Technol. 10 076007 (2021)]

Adachi (ECS J. Solid State Sci. Technol.,10, 076007(2021)) reported that an anomalous enhancement of integrated intensity of Mn4+ luminescence (IPL) in A2XF6:Mn4+ phosphors with increasing lattice temperature was an intrinsic property of the phosphors due to the increased phonon number that makes it possible to gain the parity and spin-forbidden 2Eg → 4A2g transitions.I argue in this comment that it seems still unconvincing to ascribe the anomalous increase of IPL with temperature as an intrinsic property of Mn4+-doped fluorides. Since theoretical derivations of the formulas expressing temperature dependence of the intensities were based on an unjustified assumption.

Time-dependent Pancharatnam phases and quantum correlations for coupling superconducting two-qubit system with dissipative environment

Two coupling superconducting qubits are studied for the quantum concurrence, discord, and Pancharatnam phase, for the X and Y states under the dephasing and instantaneous decay environment as well as their couplings. We find that the X and Y states are special mixed states according to the Bloch radius. In general, the larger the environment and phonon number are at the larger region of time, the larger the quantum concurrence and discord are. But we find that the environment correlations are helpful to implement the quantum computation. The Pancharatnam phases provide a way to distinguish the X and Y states.

The ground state energy of the polaron: An asymmetrical semi-exponential polar slab

In this work, the influence of the temperature (T) and RbCl asymmetrical semi-exponential confinement potential on intermediate coupling polaron in a polar slab was studied by applying the Lee-Low-Pines (LLP) unitary transformation and linear combination operation methods, based on the quantum statistical theory. We have derived the ground state energy (E0) and the mean phonon number (N). According to the obtained results, E0 increases with increasing T and parameter [Formula: see text], whereas it is a decaying function with raising parameter U0.