When an exciton acts like a hole
(Phys.org) —When is an electron hole like a quasiparticle (QP)? More specifically, what happens when a single electron hole is doped into a two-dimensional quantum antiferromagnet? Quasiparticle phenomena in such a system are predicted by theory, but have eluded observation, complicating the understanding of electron behavior in high-temperature superconducting cuprates. A team of experimenters working at the U.S. Department of Energy's (DOE's) Advanced Photon Source at Argonne National Laboratory have taken a different approach to the problem with their recent observation of an excitonic quasiparticle in strontium iridate (Sr2IrO4), a quasi-two-dimensional, spin-1/2, antiferromagnetic Mott insulator. Their work was published in Nature Communications.