Nematic order driven by superconducting correlations

Highlights: • Superconducting correlations can drive nematic order via Cooper pair delocalization. • Nematogens can be droplets of nematic topological superconductors or spin-stripes. • We present a Monte Carlo study of the interplay of nematicity and superconductivity. • A resistor network calculation captures the resistive anisotropy in KTaO${}_3$ interfaces. The interplay of nematicity and superconductivity has been observed in a wide variety of quantum materials. To explore this interplay, we consider a two-dimensional (2D) array of nematogens, local droplets with $Z_3$ nematicity, coupled to a network of Josephson junction wires. Using finite temperature classical Monte Carlo simulations, we elucidate the phase diagram of this model and show that the development of superconducting correlations and the directional delocalization of Cooper pairs can promote nematogen ordering, resulting in long-range nematic order. We obtain the transport properties of our model within an effective resistor network picture. We discuss these ideas in the context of the 2D electron gas at the (111) KTaO${}_3$ interface and the doped topological insulators Nb${}_x$Bi${}_2$Se${}_3$ and Cu${}_x$Bi${}_2$Se${}_3$. Our work makes contact with Phil Anderson's numerous contributions to broken symmetries driven by the saving of kinetic energy, including double exchange ferromagnetism and the interlayer tunneling theory of high $T_c$ superconductivity.