Charge Transport in Weyl Semimetals

Abstract

We study transport in Weyl semimetals with N isotropic Weyl nodes in the presence of Coulomb interactions or disorder at temperature T. In the interacting clean limit, we determine the conductivity σ(ω,T) by solving a quantum Boltzmann equation within a "leading log" approximation and find it to be proportional to T, up to logarithmic factors arising from the flow of couplings. In the noninteracting disordered case, we compute the Kubo conductivity and show that it behaves differently for ω << T and ω >> T: in the former regime we recover a previous result, of a finite dc conductivity and a Drude width vanishing as NT(2); in the latter, we find that σ(ω,T) vanishes linearly with ω with a leading term as T → 0 equal to the clean, free-fermion result: σ(0)((N))(ω,T = 0) = Ne(2)/12h|ω|/v(F). We compare our results to transport data on Y(2)Ir(2)O(7) and comment on the possible relevance to recent experiments on Eu(2)Ir(2)O(7).

Chiral gauge field and axial anomaly in a Weyl semimetal

“…By dimensional reduction, the (4+1)-d topological insulator is reduced to the (3+1)-d TI [8][9][10] and the Weyl fermion is reduced to (2+1)-d surface states of the TI. Weyl fermions also appear directly in (3 + 1)-d gapless electron systems, which are named as "Weyl semi-metals" 4,[11][12][13][14][15][16][17][18][19][20][21] . Since a system with both TR and parity (P) symmetries have all energy bands doubly degenerate, the Weyl semi-metal state can only be realized in a system breaking TR and/or P symmetry.…”

Long-range interaction induced phases in Weyl semimetals

“…Linearly dispersing massless fermions in three dimensions satisfy the Weyl equation and such phases of matter are the Weyl semimetals 13 . Associated with this novel low energy sector is a number of anomalous properties [14][15][16][17][18][19][20][21] .…”

Topological semimetals with helicoid surface states

“…Bloch states in the vicinity of the band crossing possess a nonzero topological index, e.g., the Chern number in case of Weyl semimetals. The nontrivial topology gives rise to anomalous bulk properties of topological semimetals such as the chiral anomaly [3][4][5]. Several classes of topological semimetals have been theoretically proposed so far, including Weyl, [2,[6][7][8][9][10][11][12][13], Dirac [14][15][16][17] and nodal line semimetals [7,[17][18][19][20][21][22][23][24][25][26][27][28][29][30], some among which have been experimentally observed [31][32][33][34][35][36][37][38][39][40][41][42][43][44][45][46][47].…”