Description:

"The Magnetic Fields of Mu2e"

Cole Kampa, PhD Student, Northwestern University

Mu2e, the muon-to-electron conversion experiment, will search for Charged Lepton Flavor Violation (CLFV), which is forbidden in the Standard Model (SM) of particle physics. The experiment, based at Fermilab, is currently in the construction phase. I will briefly describe the experimental philosophy and methods of Mu2e, as well as provide a summary of the expected sensitivity. One key improvement on previous experimental searches for muon-to-electron conversion is a precise measurement of electron momentum, which leads to better discrimination of signal and background. Understanding the magnetic field in the detectors is essential to achieve a quality momentum measurement. I will conclude by describing the unique magnetic fields of Mu2e and the strategies we use to model these fields.

"Probing for topological signatures in phase-controlled multiterminal Josephson junctions"

Maxwell Wisne, Phd Student, Northwestern University

Andreev bound states in SNS junctions depend periodically on the Josephson phase $phi$ between two superconductors, resembling the periodic dispersion of electron energy levels in a crystal lattice. A normal metal connected to n superconductors corresponds to a n-1 dimensional crystal. It has been predicted that the resulting “band structure” of such multiterminal Josephson junction devices may be topological. In the case where the normal metal is diffusive, the quasiparticle density of states at the Fermi energy varies periodically with the phases, with gapped regions separated by regions where the gap completely closes.  The dependence of the density of states can be probed by measuring the resistance of suitably designed diffusive devices.  We report on the fabrication and measurement of 3 terminal diffusive and ballistic devices, using a sample design that permits us to vary the two distinct phases independently.