Tuning the many-body interactions in a helical Luttinger liquid.

• DOI: 10.48550/arxiv.2209.10422
• Publication Date: 2022-10-20
• Authors: Junxiang Jia; Elizabeth Marcellina; Anirban Das; Michael S. Lodge; BaoKai Wang; Duc-Quan Ho; Riddhi Biswas; Tuan Anh Pham; Wei Tao; Cheng-Yi Huang; Hsin Lin; Arun Bansil; Shantanu Mukherjee; Bent Weber
• Keywords: Dielectric Constant; Strongly Correlated Electrons (cond-mat.str-el); Science; Q; FOS: Physical sciences; 541; 7. Clean energy; 01 natural sciences; Quantum; Article; Condensed Matter - Strongly Correlated Electrons; :Physics [Science]; 0103 physical sciences; Science::Physics

AbstractIn one-dimensional (1D) systems, electronic interactions lead to a breakdown of Fermi liquid theory and the formation of a Tomonaga-Luttinger Liquid (TLL). The strength of its many-body correlations can be quantified by a single dimensionless parameter, the Luttinger parameter K, characterising the competition between the electrons’ kinetic and electrostatic energies. Recently, signatures of a TLL have been reported for the topological edge states of quantum spin Hall (QSH) insulators, strictly 1D electronic structures with linear (Dirac) dispersion and spin-momentum locking. Here we show that the many-body interactions in such helical Luttinger Liquid can be effectively controlled by the edge state’s dielectric environment. This is reflected in a tunability of the Luttinger parameter K, distinct on different edges of the crystal, and extracted to high accuracy from the statistics of tunnelling spectra at tens of tunnelling points. The interplay of topology and many-body correlations in 1D helical systems has been suggested as a potential avenue towards realising non-Abelian parafermions.