Recently, room-temperature superconductivity has been reported in a nitrogen-doped lutetium hydride at near-ambient pressure [Dasenbrock-Gammon et al., Nature 615, 244 (2023)]. The superconducting properties might arise from Fm3̄m-LuH3−δNε. Here, we systematically study the phase diagram of Lu–N–H at 1 GPa using first-principles calculations, and we do not find any thermodynamically stable ternary compounds. In addition, we calculate the dynamic stability and superconducting properties of N-doped Fm3̄m-LuH3 using the virtual crystal approximation (VCA) and the supercell method. The R3m-Lu2H5N predicted using the supercell method could be dynamically stable at 50 GPa, with a Tc of 27 K. According to the VCA method, the highest Tc is 22 K, obtained with 1% N-doping at 30 GPa. Moreover, the doping of nitrogen atoms into Fm3̄m-LuH3 slightly enhances Tc, but raises the dynamically stable pressure. Our theoretical results show that the Tc values of N-doped LuH3 estimated using the Allen–Dynes-modified McMillan equation are much lower than room temperature.

Compressed hydrogen-rich compounds have received extensive attention as appealing contenders for superconductors. Here, we found several stable hydrides YZrH6, YZrH8, YZr3H16, YZrH18 and a series of metastable clathrate hexahydrides in...

Within the theoretical framework of Kubo formula and self-consistent Born approximation, we theoretically study the transversal and longitudinal magneto-conductivity of a type-I Weyl semimetal. We focus mainly on the peculiar role of inter-valley scattering on linear transversal magnetoresistance (LTMR) and negative longitudinal magnetoresistance (NLMR). At first, we find that the contributions of high-order Feynman diagrams to the transversal magneto-conductivity play the distinct roles between the cases of intra- and inter-valley scatterings. The former suppresses the transversal conductivity whereas the latter enhances it. Then, with the increase of scattering strength, the LTMR is destroyed, accompanying a sizable increase of transversal conductivity, in particular, in the case of the tilted cone. For longitudinal magneto-transport, inter-valley scattering contributes only trivial magnetoresistance. In contrast, intra-valley scattering is invalid for longitudinal magneto-transport which means a very large NLMR. In addition, the high-order Feynman diagrams always play the nontrivial role on the longitudinal conductivity even in the weak scattering limit. Finally, when altering the Fermi energy among low-lying Landau level, the peaks of transversal conductivity just correspond to the valleys of the longitudinal conductivity.

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