Sondheimer oscillations as a probe of non-ohmic flow in type-II Weyl semimetal WP${}_2$

Abstract

As conductors in electronic applications shrink, microscopic conduction processes lead to strong deviations from Ohm's law. Depending on the length scales of momentum conserving ($l_{MC}$) and relaxing ($l_{MR}$) electron scattering, and the device size ($d$), current flows may shift from ohmic to ballistic to hydrodynamic regimes and more exotic mixtures thereof. So far, an in situ, in-operando methodology to obtain these parameters self-consistently within a micro/nanodevice, and thereby identify its conduction regime, is critically lacking. In this context, we exploit Sondheimer oscillations, semi-classical magnetoresistance oscillations due to helical electronic motion, as a method to obtain $l_{MR}$ in micro-devices even when $l_{MR}\gg d$. This gives information on the bulk $l_{MR}$ complementary to quantum oscillations, which are sensitive to all scattering processes. We extract $l_{MR}$ from the Sondheimer amplitude in the topological semi-metal WP${}_2$, at elevated temperatures up to $T\sim 50$~K, in a range most relevant for hydrodynamic transport phenomena. Our data on micrometer-sized devices are in excellent agreement with experimental reports of the large bulk $l_{MR}$ and thus confirm that WP${}_2$ can be microfabricated without degradation. Indeed, the measured scattering rates match well with those of theoretically predicted electron-phonon scattering, thus supporting the notion of strong momentum exchange between electrons and phonons in WP${}_2$ at these temperatures. These results conclusively establish Sondheimer oscillations as a quantitative probe of $l_{MR}$ in micro-devices in studying non-ohmic electron flow.

arXiv comment14 pages with 4 figures

References in corpus (22)

• Restoring the density-gradient expansion for exchange in solids and surfaces
• Generalized gradient approximation for solids and their surfaces
• Ultrahigh mobility and giant magnetoresistance in the Dirac semimetal Cd${}_3$As${}_2$
• Evidence for hydrodynamic electron flow in PdCoO${}_2$
• JDFTx: software for joint density-functional theory
• Electron Viscosity, Current Vortices and Negative Nonlocal Resistance in Graphene
• Visualizing Poiseuille flow of hydrodynamic electrons
• Electrical and Thermal Transport at the Planckian Bound of Dissipation in the Hydrodynamic Electron Fluid of WP2
• Extremely high magnetoresistance and conductivity in the type-II Weyl semimetals WP2 and MoP2
• Numerical extraction of de Haas - van Alphen frequencies from calculated band energies
• Robust Type-II Weyl Semimetal Phase in Transition Metal Diphosphides XP${}_2$ (X = Mo, W)
• Tantalum Monoarsenide: an Exotic Compensated Semimetal
• Electron scattering in tantalum monoarsenide
• Extremely large magnetoresistance in a topological semimetal candidate pyrite PtBi2
• Departure from the Wiedemann-Franz Law in WP${}_2$ Driven by Mismatch in $T$-square Resistivity Prefactors
• Inducing superconductivity in Weyl semi-metal microstructures by selective ion sputtering
• Unusual magneto-transport from Si-square nets in topological semimetal HfSiS
• Microscopic Origins of Hydrodynamic Transport in Type-II Weyl Semimetal WP${}_2$
• Uncovering Electron-Phonon Scattering and Phonon Dynamics in Type-I Weyl Semimetals
• Evidence for dominant phonon-electron scattering in Weyl semimetal WP${}_2$
• Fermi surface of the Weyl type-II metallic candidate WP2
• A Review on Quantum Computing: Qubits, Cryogenic Electronics and Cryogenic MOSFET Physics

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