Nonlocal and Local Thermoelectricity in Topological Nanosystems

Nonlocal and Local Thermoelectricity in Topological Nanosystems - Featured

Title: Nonlocal and Local Thermoelectricity in Topological Nanosystems
When: Thursday, January 16, 2025, 12:00
Place: Department of Theoretical Condensed Matter Physics, Faculty of Sciences, Module 5, Seminar Room (5th Floor)
Speaker: Alessandro Braggio, CNR-Nano and NES Scuola Normale Superiore, Italy.

We discuss two recent examples of how thermoelectricity could uniquely emerge in topological systems. The first example shows how nonlocal thermoelectricity can be used to detect interaction-mediated heat exchange in electronic 1D channels. Interacting systems out-of-equilibrium are challenging problems in mesoscopic physics, especially in quantum Hall systems where the electronic coherent nature and interactions make the physics very complex[1,2]. Hereafter, we propose the nonlocal thermoelectric response as a direct detector of the interactions, nonthermal states and the effect of correlations[3]. By a proper design, we expect a thermoelectrical response only when the electron-electron interaction mediates heat exchange between the channels and directly measures the interaction strength. We compute the charge and energy currents and noises of a non-equilibrium integrable interacting system for zero-range interactions, determining the universal interaction-dependent length scale of the energy equilibration in a Luttinger liquid. The second example is the observation of a strong electron-hole asymmetry at the centre of a topological impurity, the Abrikosov vortex, for a type II superconductor, when the temperature is within the quantum limit. In this case, this strong breaking will determine a strong thermoelectrical effect up to mV/K at subKelvin temperatures[4].

References

  1. C. Altimiras, H. le Sueur, U. Gennser, A. Cavanna, D. Mailly, and F. Pierre, , Nat. Phys. 6 (2010) 34.
  2. K. Itoh, R. Nakazawa, T. Ota, M. Hashisaka, K. Muraki, and T. Fujisawa, Phys. Rev. Lett. 120 (2018), 197701.
  3. A. Braggio, M. Carrega, B. Sothmann, R. Sánchez, Phys. Rev. Research 6 (2024) L012049.
  4. A. N. Singh, B. Bhandari, A. Braggio, F. Giazotto, A. Jordan Phys. Rev. Lett. 133 (2024) 256002.