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Shu-Yu Zheng

Publications and source records attributed to Shu-Yu Zheng.

2 recordsLinked to original sources

Joule heating and electronic Gurzhi effect in hydrodynamic differential transport in an electron liquid

We perform a differential resistance study in the hydrodynamic regime of electron liquid in GaAs/AlGaAs quantum wells. At zero magnetic field ($B$) a Lorentzian profile occurs in the nonlinear transport driven by a U-turn (ac) current loop, in (ac + dc) measurements a minimum deepens with the external dc current bias ($j_{dc}$). Our analysis shows that the observed electronic transport valley induced by $j_{dc}$ is attributed to Joule heating effect on the electron temperature ($T_{e}$) of electron liquid. Quantitatively, we demonstrate that the viscosity resistivity ($Δρ$) is proportional to $T^{-2}$ and is consistent with the dc-current induced electronic Gurzhi effect in various configurations of measurement.

cond-mat.mes-hall

Resonances involving integer magnons and spin-1/2 excitations in a magnetism modulated two-dimensional electron gas

We conduct an experimental study of high-mobility two-dimensional electron gas (2DEG) in GaAs/AlGaAs quantum wells modulated by strong magnetism at an in-plane magnetic field ($B$). The modulated $B$-fields are performed via the single stripe and gratings which are made of the heavy rare earth metal Terbium (Tb) thin films on the sample surface. The robust ferromagnetic resonances (FMRs) persist to the temperature of 50-70 K in both the stripe and grating samples, for the ferromagnetism (FM) phase of Tb exists at above 100 K. The high-order (with integer numbers of $j \equiv \hbarω/gμ_{B}B = 1, 2,$...) magnetic resonances can also be observed in the stripe structure via the microwave (MW) photovoltaic detection and magnetoresistance under microwave irradiation. In addition, the resonance features around $j = 1/2$ are robust in the single-stripe modulated sample, which suggests the spinons with spin-1/2 collective excitations in a 1D Heisenberg model.

cond-mat.mes-hall