A study in China published in Nature Communications revealed the Non-saturating quantum magnetization in Weyl semimetal TaAs.

The work was jointly conducted by Dr. ZHANG Jinglei from High Magnetic Field Laboratory, Chinese Academy of Sciences (CHMFL), Prof. JIA Shuang from Perking University and Prof. LU Haizhou from Southern University of Science and Technology.

The low-energy states of electrons in topological materials could be described as a series of quasiparticles, which obeys different representations of the Dirac equation.

The unique topological nature promises many novel properties belonging to the massless quasiparticles, such as linear energy dispersion, monopoles, and Fermi arcs on the surface.

Detecting the spectroscopic signatures of relativistic quasiparticles in emergent topological materials is crucial for searching their potential applications.

Magnetometry is a powerful tool for fathoming electrons in solids, by which a clear method for discerning relativistic quasiparticles has not yet been established.

In this study, scientists probed magnetic torque and parallel magnetization for the archetype Weyl semimetal TaAs in strong magnetic field.

They observed a quasi-linear field dependent effective transverse magnetization and a non-saturating parallel magnetization when the system entered the quantum limit.

Distinct from the saturating magnetic responses for non-relativistic quasiparticles, the non-saturating signals of TaAs in strong field was consistent with newly developed magnetization calculation for a Weyl fermion system in an arbitrary angle.

These findings may establish a high-field thermodynamic method for detecting the magnetic response of relativistic quasiparticles in topological materials.

This work was supported by the Youth Innovation Promotion Association the Chinese Academy of Sciences (CAS), the Scientific Instrument Developing Project of CAS and the Innovative Program of Development Foundation of Hefei Center for Physical Science and Technology.