Related papers: Strong Anharmonic and Quantum Effects in Pm-3n AlH…
The interplay between electron correlation and nuclear quantum effects makes our understanding of elemental hydrogen a formidable challenge. Here, we present the phase diagram of hydrogen and deuterium at low temperatures and high-pressure…
The comparison study of high pressure superconducting state of recently synthesized H$_3$S and PH$_3$ compounds are conducted within the framework of the strong-coupling theory. By generalization of the standard Eliashberg equations to…
Amongst the X(Sn,Pb)Y$_3$ perovskites currently under scrutiny for their photovoltaic applications, the cubic B-$\alpha$ phase of CsSnI$_3$ is arguably the best characterized experimentally. Yet, according to the standard harmonic theory of…
We present a brief review of some recent work on the problem of highest achievable temperature of superconducting transition $T_c$ in electron-phonon systems. The discovery of record-breaking values of $T_c$ in quite a number of hydrides…
We show that the electron-phonon coupling (EPC) in many materials can be significantly underestimated by the standard density functional theory (DFT) in the local density approximation (LDA) due to large non-local correlation effects. We…
Superconductivity has been one of the focal points in medium and high-entropy alloys (MEAs-HEAs) since the first discovery of the HEA superconductor in 2014. Until now, most HEAs' superconducting transition temperature (Tc) has not exceeded…
We present a workflow that iteratively combines \textit{ab-initio} calculations with a machine-learning (ML) guided search for superconducting compounds with both dynamical stability and instability from imaginary phonon modes, the latter…
KTaO${}_{3}$ presents a rich hyper-Raman spectrum originating from two-phonon processes at the Brillouin zone boundary, indicating the possibility of driving these phonon modes using intense midinfrared laser sources. We obtained the…
Recently, an alkaline earth hydride CaH$_6$ having a sodalitelike clathrate structure has been experimentally synthesized at megabar pressures with a maximum $T_c$ of 215 K, comparable to that of a rare earth hydride LaH$_{10}$. Here, based…
The highest superconducting temperature T$_c$ observed in any elemental metal (Li with T$_c$ ~ 20 K at pressure P ~ 40 GPa) is shown to arise from critical (formally divergent) electron-phonon coupling to the transverse T$_1$ phonon branch…
We report the first principles investigations on the phonons of three polytypes of BaTiO3 (BTO): paraelectric (PE) cubic Pm-3m and two ferroelectric (FE) phases, tetragonal P4mm and rhombohedral R3m. The phonon frequencies calculated using…
We report on far- and mid-infrared reflectivity of NdMnO3 from 4 K to 300K. Two main features are distinguished in the infrared spectra: active phonons in agreement with the expected for orthorhombic D2h 16-Pbnm (Z=4) space group remaining…
Phonons, quantized vibrations of the atomic lattice, are fundamental to understanding thermal transport, structural stability, and phase behavior in crystalline solids. Despite advances in computational materials science, most predictions…
We investigate the electronic and phonon properties of hydrogen sulfide (SH$_3$) under ultrahigh pressure to elucidate the origin of its high-T$_c$ superconductivity. Contrary to the prevailing belief that the metalized S-H $\sigma$ bond is…
The discovery of near-room-temperature superconductivity in compressed hydrides has sparked intensive research efforts to identify superconducting hydrides stable at low or even ambient pressures. Herein, we demonstrate a new mechanism for…
The structural, electronic, lattice dynamics, electron-phonon coupling, and superconducting properties of the alkali-metal hydride RbH, metalized through electron-doping by the construction of the solid-solution Rb$_{1-x}$Sr$_x$H, are…
We investigate non-perturbative features of a three-dimensional Abelian Higgs model with singly- and doubly-charged scalar fields coupled to a single compact Abelian gauge field. The model is pretending to describe various planar systems of…
Structural evolution of a prospective hydrogen storage material, ammonia borane NH3BH3, has been studied at high pressures up to 12 GPa and at low temperatures by synchrotron powder diffraction. At 293 K and above 1.1 GPa a disordered I4mm…
The Korringa-Kohn-Rostoker method with the coherent potental approximation (KKR-CPA) is applied to study the first superconducting high entropy alloy (HEA) Ta34Nb33Hf8Zr14Ti11 (discovered in 2014 with Tc = 7.3 K), focusing on estimations of…
Two hydrogen-rich materials, H$_3$S and LaH$_{10}$, synthesized at megabar pressures, have revolutionized the field of condensed matter physics providing the first glimpse to the solution of the hundred-year-old problem of room temperature…