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MON: Monday Contributed Sessions
MON 22: Quantum Transport II
MON 22.4: Talk
Monday, September 8, 2025, 17:15–17:30, ZHG104
Influence of Electron Density on Giant Negative Magnetoresistance — •Lina Bockhorn1, Christian Reichl2, Werner Wegscheider2, and Rolf J. Haug1 — 1Institut für Festkörperphysik, Leibniz Universität Hannover, Germany — 2Laboratorium für Festkörperphysik, ETH Zürich, Switzerland
Ultra-high mobility two-dimensional electron gases often exhibit a remarkably robust negative magnetoresistance at zero magnetic field. Below 800 mK, this phenomenon divides into two distinct parts [1-4]: a temperature-independent narrow peak around B=0 T, arising from the interplay of smooth disorder and elastic scattering at macroscopic defects [2, 3], and a temperature-dependent giant negative magnetoresistance (GNMR) at higher magnetic fields. The theoretical understanding of the GNMR remains an open question, as it involves several independent parameters in addition to electron-electron interaction, possibly leading to hydrodynamic transport effects. To gain insights into the nature of GNMR, we investigate this effect as a function of electron density at various temperatures and currents. Our results show a significant dependence of GNMR on electron density [4], suggesting that variations in scattering potentials [5] are not considered appropriately in theoretical models.
[1] L. Bockhorn et al., Phys. Rev. B 83, 113301 (2011).
[2] L. Bockhorn et al., Phys. Rev. B 90, 165434 (2014).
[3] L. Bockhorn et al., Appl. Phys. Lett. 108, 092103 (2016).
[4] L. Bockhorn et al., Phys. Rev. B 109, 205416 (2024).
[5] Y. Huang et al., Phys. Rev. Materials 6, L061001 (2022).
Keywords: giant negative magnetoresistance; electron-electron interaction