Magnetic field dependence of ρxx, ρxy and ρzz with field up to 59 T, respectively.
(Phys. Rev. B 102, 245135; https://doi.org/10.1103/PhysRevB.102.245135)
The charge-density-wave (CDW) is a ground state with spontaneous symmetry broken which is always accompanied by a commensurate/incommensurate periodic lattice distortion and a charge density modulation. Generally, the Zeeman splitting of the bands at the Fermi level will reduce the pairing interaction for increasing fields. This eventually results in a non-condensate, metallic state where the energy gap can be driven to zero. η-Mo4O11 is a typical quasi-2D CDW material, which exhibits a lot of interesting properties such as possible quantum Hall effect and sliding motion of CDW. However, the high-field transport behaviors in η-Mo4O11 is still an open question.
What we discover?
Based on the pulsed magnetic field, we study the in-plane, out-of-plane MR and Hall resistance for η-Mo4O11 up to 59 T. Above the quantum limit (QL), fast quantum oscillations (QOs) with complex frequencies have been found in both MR and Hall resistance, allowing for direct exploration and study of FS properties. At higher field of 45 T, we have observed a pronounced phase transition of a sudden increase in interlayer MR. In addition, the fast QOs show increasing periodicities depending on magnetic field range and Hall resistance exhibits a corresponding tendency of towards zero, implying that the carrier density increases with magnetic field. Our finding supports the emergence of the unreconstructed FS at high field as the CDW is suppressed.
Why is this important?
Understanding the evolution of electronic structure in high magnetic field is important, and the interplay between the magnetic field and CDW is widely investigated including high-temperature cuprate superconductors. The striking QO features beyond the QL in η-Mo4O11 thus signify a previously unknown reconstructed FS topology in the high-field state with several revived “nested or vanishing” bands, leading to a good understanding of its quasi-2D nature and providing an ideal platform to investigate other exotic physical phenomena in related CDW systems.
Why did we need WHMFC?
In this work, the fast QOs occurs beyond the QL which only can be reached by the pulsed field. In WHMFC, we rely on the high-field transport platform, which can provide 59 T pulsed magnetic field, to systematically study the magnetoresistance and Hall effect in this compound.
Who did the research?
Jiezun Ke, Ming Yang, Haipeng Zhu, Congbin Liu, Chao Dong, Wanxin Liu, Mengyi Shi, Junfeng Wang
Wuhan National High Magnetic Field Center and School of Physics, Huazhong University of Science and Technology, Wuhan 430074, China
This work was supported by the National Natural Science Foundation of China (Grants No. 12004122, No. U1832214 and No. 12074135), the Fundamental Research Funds for the Central Universities (Grant No. 2018KFYXKJC005).