{'fraction_non_alphanumeric': 0.011587485515643106, 'fraction_numerical': 0.005793742757821553, 'mean_word_length': 5.306569343065694, 'pattern_counts': {'":': 0, '<': 0, '<?xml version=': 0, '>': 0, 'https://': 0, 'lorem ipsum': 0, 'www.': 0, 'xml': 0}, 'pii_count': 0, 'substrings_counts': 0, 'word_list_counts': {'cursed_substrings.json': 0, 'profanity_word_list.json': 0, 'sexual_word_list.json': 0, 'zh_pornsignals.json': 0}}
Intrinsic optical conductivity of a C 2 v symmetric topological insulator

In this work we analytically investigate the longitudinal optical conductivity of the C 2 v symmetric topological insulator. The conductivity expressions at T = 0 are derived using the Kubo formula and expressed as a function of the ratio of the Dresselhaus and Rashba parameters that characterize the low-energy Hamiltonian. We find that the longitudinal inter-band conductivity vanishes when Dresselhaus and Rashba parameters are equal in strength, also called the persistent spin helix state. The calculations are extended to obtain the frequency-dependent real and imaginary components of the optical conductivity for the topological Kondo insulator SmB6 which exhibits C 2 v symmetric and anisotropic Dirac cones hosting topological states at X ¯ point on the surface Brillouin zone.