arXiv subjects

Yonatan Messica

Publications and source records attributed to Yonatan Messica.

5 recordsLinked to original sources

arXiv2026

Odd-viscosity-induced instability in shear flows

Odd viscosity is a nondissipative component of the viscosity tensor that arises in fluids with broken time-reversal symmetry. Despite conserving energy, we show that odd viscosity can qualitatively alter hydrodynamic stability by generating exponentially growing modes that are absent in conventional fluids. For plane Poiseuille flow, we derive the odd-viscous generalization of the Orr--Sommerfeld--Squire equations and find a new instability that first emerges for spanwise perturbations and extends to oblique modes through the amplification of odd-viscous forces in critical layers. The instability originates from the non-normal dynamics of shear flows: conventional fluids support transiently growing disturbances through the lift-up mechanism, while odd viscosity provides a feedback between wall-normal velocity and vorticity that converts this transient growth into a self-sustaining exponentially growing mode. More generally, we show that an energy-conserving perturbation can destabilize a non-normal dynamical system only when the unperturbed system supports transient growth. Our results establish a direct connection between transient growth, non-normality, and instability induced by nondissipative forces, with implications extending beyond odd-viscous hydrodynamics.

physics.flu-dyn↗

arXiv2025

Stokes flow in an electronic fluid with odd viscosity

We investigate the transition between elastic and viscous regimes for time-reversal broken Weyl semimetals. In these materials, Hall transport occurs through two parallel channels: the Fermi sea and the Fermi surface. The Fermi sea part remains unaffected by electron-electron scattering, whereas the Fermi surface is influenced by it. We model the disorder by dilute impenetrable spherical impurities. We analyze the flow of an electronic fluid with a finite odd viscosity in the presence of such disorder and compute the conductivity tensor. We find that in the generic case of finite intrinsic conductivity, the Hall angle in the viscous regime is parametrically suppressed compared to the elastic regime. In the special case where the intrinsic conductivity vanishes, the ratio between the transverse and the longitudinal resistivities matches the ratio between the odd and even components of the viscosity tensor.

cond-mat.mes-hall↗

arXiv2024

Hall Coulomb drag induced by electron-electron skew scattering

We study the influence of spin-orbit interaction on electron-electron scattering in the Coulomb drag setup. We study a setup made of a time-reversal-symmetry-broken Weyl semimetal (WSM) layer and a normal metal layer. The interlayer drag force consists of two components. The first one is conventional and is parallel to the relative electronic boost velocity between the layers. This part of the drag tends to equilibrate the momentum distribution in the two layers, analogous to shear viscosity in hydrodynamics. In the WSM layer, the shift of the Fermi surface is not parallel to the electric field, due to skew scattering in the WSM. This induces a Hall current in the normal metal via the conventional component of the drag force. The second component of the drag force is perpendicular to the boost velocity in the Weyl semimetal and arises from interlayer e-e skew scattering, which results from two types of processes. The first process is an interference between electron-electron and electron-disorder scattering. The second process is due to the side jumps in electron-electron collisions in an external electric field. Both the parallel and perpendicular components of the drag are important for the anomalous Hall drag conductivity. On the other hand, for the Hall drag resistivity, the contribution from the parallel friction is partially cancelled in a broad temperature regime. This work provides insight into the microscopic mechanisms of Hall-like friction in electronic fluids.

cond-mat.mes-hall↗

arXiv2023

Anomalous Hall effect in disordered Weyl semimetals

We study the anomalous Hall effect in a disordered Weyl semimetal. While the intrinsic contribution is expressed solely in terms of Berry curvature, the extrinsic contribution is given by a combination of the skew scattering and side jump terms. For the model of small size impurities, we are able to express the skew scattering contribution in terms of scattering phase shifts. We identify the regime in which the skew scattering contribution dominates the side-jump contribution: the impurities are either strong or resonant, and at dilute concentration. In this regime, the Hall resistivity $ρ_{xy}$ is expressed in terms of two scattering phases, analogous to the s-wave scattering phase in a non-topological metal. We compute the dependence of $ρ_{xy}$ on the chemical potential, and show that $ρ_{xy}$ scales with temperature as $T^2$ in low temperatures and as $T^{3/2}$ in the high temperature limit.

cond-mat.mes-hall↗

arXiv2023

Heat transport in Weyl semimetals in the hydrodynamic regime

We study heat transport in a Weyl semimetal with broken time-reversal symmetry in the hydrodynamic regime. At the neutrality point, the longitudinal heat conductivity is governed by the momentum relaxation (elastic) time, while longitudinal electric conductivity is controlled by the inelastic scattering time. In the hydrodynamic regime this leads to a large longitudinal Lorenz ratio. As the chemical potential is tuned away from the neutrality point, the longitudinal Lorenz ratio decreases because of suppression of the heat conductivity by the Seebeck effect. The Seebeck effect (thermopower) and the open circuit heat conductivity are intertwined with the electric conductivity. The magnitude of Seebeck tensor is parametrically enhanced, compared to the non-interacting model, in a wide parameter range. While the longitudinal component of Seebeck response decreases with increasing electric anomalous Hall conductivity $σ_{xy}$, the transverse component depends on $σ_{xy}$ in a non-monotonous way. Via its effect on the Seebeck response, large $σ_{xy}$ enhances the longitudinal Lorenz ratio at a finite chemical potential. At the neutrality point, the transverse heat conductivity is determined by the Wiedemann-Franz law. Increasing the distance from the neutrality point, the transverse heat conductivity is enhanced by the transverse Seebeck effect and follows its non-monotonous dependence on $σ_{xy}$.

cond-mat.mes-hall↗