Discrete Scale Invariance in Topological Semimetals

Weyl and Dirac semimetals show anomalous quantum oscillations in the their magnetoresistance.  When the magnetic field B exceeds the quantum limit, the oscillations are periodic in ln B.  This is very unexpected and utterly unlike previously observed Aharonov-Bohm and Schubnikov -deHaas oscillations.  I show that the oscillations come from bound states of Coulomb impurities whose binding energies form a geometric progression. This is a signature of discrete scale invariance. The oscillations have now been seen in several Weyl semimetals in different types of experiments.  I'll focus on ZrTe5.

Short Bio

Robert Joynt received his Ph.D. from the University of Maryland in 1982 and was a postdoctoral fellow at the Cavendish Laboratory of the University of Cambridge and the Institute for Theoretical Physics at ETH-Zurich.  From 1986-2023 he was Professor of Physics at the University of Wisconsin-Madison, where he also served as Department Chair.  His research in condensed matter physics has ranged from the quantum Hall effect to high-Tc superconductivity to superfluidity in neutron stars. In quantum computing, active areas include semiconductor qubits, quantum correlations, and error correction schemes for neutral atom systems.  At present he is researching ways to speed up the quantum optimization algorithms, decoherence from evanescent-wave Johnson noise, and new designs for qubit devices.