Researchers at JILA simulated superconductivity in strontium atoms within an optical cavity to observe rare dynamic phases, including the elusive Phase III, which has implications for quantum physics and technology development.
In physics, scientists have been fascinated by the mysterious behavior of superconductors—materials that can conduct electricity with zero resistance when cooled to extremely low temperatures. Within these superconducting systems, electrons team up in “Cooper pairs” because they’re attracted to each other due to vibrations in the material called phonons.
As a thermodynamic phase of matter, superconductors typically exist in an equilibrium state. But recently, researchers at JILA became interested in kicking these materials into excited states and exploring the ensuing dynamics. As reported in a new Nature paper, the theory and experiment teams of JILA and NIST Fellows Ana Maria Rey and James K. Thompson, in collaboration with Prof. Robert Lewis-Swan at the University of Oklahoma, simulated superconductivity under such excited conditions using an atom-cavity system.
Instead of dealing with actual superconducting materials, the scientists harnessed the behavior of strontium atoms, laser-cooled to 10 millionths of a degree above absolute zero and levitated within an optical cavity built out of mirrors. In this simulator, the presence or absence of a Cooper pair was encoded in a two-level system or qubit. In this unique setup, photon-mediated interactions between electrons were realized between the atoms within the cavity.
Thanks to their simulation, the researchers observed three distinct phases of superconducting dynamics, including a rare “Phase III” featuring persistent oscillatory behavior predicted by condensed matter physics theorists but never before observed.
These findings could pave the way for a deeper understanding of superconductivity and its controllability, offering new avenues for engineering unique superconductors. Moreover, it holds promise for enhancing the coherence time for quantum sensing applications, such as improving the sensitivity of optical clocks.
To read more, click here.