Superconductivity in the doped quantum spin liquid on the triangular lattice*

Broad interest in quantum spin liquid (QSL) phases was triggered by the notion that they can be viewed as insulating phases with preexisting electron-pairs, such that upon light doping they might automatically yield high temperature superconductivity. Yet despite intense efforts, definitive evidence showing that doping QSLs leads to superconductivity has been lacking. We address the problem of a lightly doped QSL through a large-scale density-matrix renormalization group study of the t-J model on the triangular lattice with a small but non-zero concentration of doped holes. We provide direct evidences that doping QSL can naturally give rise to superconductivity. The ground state is consistent with a Luther-Emery liquid with power-law superconducting and charge-density-wave correlations but short-range spin-spin correlations. Specifically, the superconducting correlations are the dominant correlations on both four-leg and six-leg cylinders, indicating that long-range superconductivity would emerge in doping QSL in two dimensions.