Scattering Atoms Catch the d Wave

Gases of ultracold atoms provide an exquisite platform for exploring models of condensed-matter physics. The atoms, which act as stand-ins for electrons or other degrees of freedom in solids and fluids, can be controlled by researchers with great finesse, allowing atomic systems to simulate exotic forms of magnetism, quantum phase transitions, and other traditionally condensed-matter phenomena. However, simulating high-temperature superconductivity has been a tougher nut to crack, since the electrons in this phase experience a particular pairwise interaction that is spatially anisotropic. This so-called d-wave (Fig. 1) [1] interaction is difficult to emulate with atoms at suitably low temperatures. Working with ultracold rubidium atoms, a team led by Li You at Tsinghua University, China, has succeeded in creating the desired d-wave interactions at low temperatures by using a magnetic field to induce a scattering resonance between the atoms [2]. Unlike electrons, which are fermions, the atoms the team works with are bosons—an important distinction. Nonetheless, the new work provides an essential ingredient to begin exploring simulations of high-temperature superconductivity as well as other many body phases that involve d-wave interactions.