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M. Schütt

Publications and source records attributed to M. Schütt.

21 records · Page 2Linked to original sources

Collision-dominated nonlinear hydrodynamics in graphene

We present an effective hydrodynamic theory of electronic transport in graphene in the interaction-dominated regime. We derive the emergent hydrodynamic description from the microscopic Boltzmann kinetic equation taking into account dissipation due to Coulomb interaction and find the viscosity of Dirac fermions in graphene for arbitrary densities. The viscous terms have a dramatic effect on transport coefficients in clean samples at high temperatures. Within linear response, we show that viscosity manifests itself in the nonlocal conductivity as well as dispersion of hydrodynamic plasmons. Beyond linear response, we apply the derived nonlinear hydrodynamics to the problem of hot spot relaxation in graphene.

cond-mat.mes-hall↗

Hydrodynamics in graphene: Linear-response transport

We develop a hydrodynamic description of transport properties in graphene-based systems which we derive from the quantum kinetic equation. In the interaction-dominated regime, the collinear scattering singularity in the collision integral leads to fast unidirectional thermalization and allows us to describe the system in terms of three macroscopic currents carrying electric charge, energy, and quasiparticle imbalance. Within this "three-mode" approximation we evaluate transport coeffcients in monolayer graphene as well as in double-layer graphene-based structures. The resulting classical magnetoresistance is strongly sensitive to the interplay between the sample geometry and leading relaxation processes. In small, mesoscopic samples the macroscopic currents are inhomogeneous which leads to linear magnetoresistance in classically strong fields. Applying our theory to double-layer graphene-based systems, we provide microscopic foundation for phenomenological description of giant magnetodrag at charge neutrality and find magnetodrag and Hall drag in doped graphene.

cond-mat.mes-hall↗

Coulomb drag in graphene near the Dirac point

We study Coulomb drag in double-layer graphene near the Dirac point. A particular emphasis is put on the case of clean graphene, with transport properties dominated by the electron-electron interaction. Using the quantum kinetic equation framework, we show that the drag becomes $T$-independent in the clean limit, $Tτ\to \infty$, where $T$ is temperature and $1/τ$ impurity scattering rate. For stronger disorder (or lower temperature), $Tτ\ll 1/α^2$, where $α$ is the interaction strength, the kinetic equation agrees with the leading-order ($α^2$) perturbative result. At still lower temperatures, $Tτ\ll 1$ (diffusive regime) this contribution gets suppressed, while the next-order ($α^3$) contribution becomes important; it yields a peak centered at the Dirac point with a magnitude that grows with lowering $Tτ$.

cond-mat.mes-hall↗