Magnetic field control over the axial character of Higgs modes in charge-density wave compounds

Abstract

Understanding how symmetry-breaking processes generate order out of disorder is among the most fundamental problems of nature. The scalar Higgs mode - a massive (quasi-) particle - is a key ingredient in these processes and emerges with the spontaneous breaking of a continuous symmetry. Its related exotic and elusive axial counterpart, a Boson with vector character, can be stabilized through the simultaneous breaking of multiple continuous symmetries. Here, we employ a magnetic field to tune the recently discovered axial Higgs-type charge-density wave amplitude modes in rare-earth tritellurides. We demonstrate a proportionality between the axial Higgs component and the applied field, and a 90 degrees phase shift upon changing the direction of the magnetic field. This indicates that the axial character is directly related to magnetic degrees of freedom. Our approach opens up an in-situ control over the axial character of emergent Higgs modes.