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Landau level splitting in Cd3As2 under high magnetic fields.
Junzhi Cao1,2, Sihang Liang1,2, Cheng Zhang1,2
1State Key Laboratory of Surface Physics and Department of Physics, Fudan University, Shanghai 200433, China.
Nature Communications
|July 14, 2015
Summary
This study explores three-dimensional topological Dirac semimetals (TDSs) using transport experiments. Researchers observed Landau level splitting, indicating symmetry breaking and a potential pathway to Weyl semimetals.
Area of Science:
- Condensed matter physics
- Materials science
- Topological materials
Background:
- Three-dimensional topological Dirac semimetals (TDSs) exhibit linear energy dispersion, analogous to 3D graphene.
- TDSs can transition to other exotic phases like Weyl semimetals by breaking symmetries.
Purpose of the Study:
- To investigate Landau level splitting in Cd3As2 single crystals under high magnetic fields.
- To explore the role of symmetry breaking, particularly time-reversal symmetry, in TDSs.
- To demonstrate a method for generating a Weyl semimetal phase from TDSs.
Main Methods:
- Transport experiments on Cd3As2 single crystals.
- Application of high magnetic fields.
- Analysis of Landau level splitting and Berry phase.
Main Results:
- Observed Landau level splitting, suggesting removal of spin degeneracy via time-reversal symmetry breaking.
- Detected an angular dependence in the Berry phase.
- Observed a crossover in the Berry phase from non-trivial to trivial under high magnetic fields.
Conclusions:
- Symmetry breaking plays a crucial role in the behavior of TDSs.
- The findings suggest a competition between orbit-coupled field strength and field-generated mass term.
- This research demonstrates a viable route to creating Weyl semimetal phases by breaking time-reversal symmetry.
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