Berkeley collaboration reveals the physics of unconventional superconductors

Friday, December 3, 2021

A collaborative effort between several research groups in Berkeley Physics has yielded results on the unconventional superconductor CeColn5, published today in Science.

Exotic many-body quantum states underlie unconventional superconductivity

The mystery of high temperature superconductivity has eluded scientists for decades. One point that is clear is that the phenomenon is intertwined with the magnetic interactions between the electrons. In conventional materials such interactions lead to magnetic order. However, in unconventional superconductors a combination of complexity and magnetic frustration is thought to lead to more exotic states that are not magnetically ordered, but are highly quantum entangled. Graduate student Nikola Maksimovic and co-workers discovered that in the unconventional superconductor CeCoIn5, a quantum state consistent with this picture might describe the zero-temperature properties. The study leveraged techniques in single crystals synthesis in the James Analytis group to chemically dope these materials and tune them between their magnetic and superconducting states. Maksimovic measured the electronic density of these materials using magnetic fields of up to 75T - some of the largest available on earth. Then, using spectroscopic techniques in the Alessandra Lanzara group, the collaboration imaged the electronic energy structure as a function of this doping. Together with theory from the Ehud Altman group at Berkeley, the team demonstrated that such a highly quantum entangled quantum state may underlie the mechanism of unconventional superconductivity."

Read it here.