Abstract
It has long been realized that even a perfectly clean electronic system harbors a Landauer-Sharvin resistance, inversely proportional to the number of its conduction channels. This resistance is usually associated with voltage drops on the system’s contacts to an external circuit. Recent theories have shown that hydrodynamic effects can reduce this resistance, raising the question of the lower bound of resistance of hydrodynamic electrons. Here, we show that by a proper choice of device geometry, it is possible to spread the Landauer-Sharvin resistance throughout the bulk of the system, allowing its complete elimination by electron hydrodynamics. We trace the effect to the dynamics of electrons flowing in channels that terminate within the sample. For ballistic systems this termination leads to back-reflection of the electrons and creates resistance. Hydrodynamically, the scattering of these electrons off other electrons allows them to transfer to transmitted channels and avoid the resistance. Counterintuitively, we find that in contrast to the ohmic regime, for hydrodynamic electrons the resistance of a device with a given width can decrease with its length, suggesting that a long enough device may have an arbitrarily small total resistance.
Original language | English |
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Article number | 157701 |
Journal | Physical review letters |
Volume | 129 |
Issue number | 15 |
DOIs | |
Publication status | Published - 7 Oct 2022 |
Bibliographical note
Funding Information:We thank L. Ella, G. Falkovich, L. Levitov, M. Polini, M. Shavit, A. Rozen, A. V. Shytov and U. Zondiner for useful discussions. Work was supported by the Leona M. and Harry B. Helmsley Charitable Trust grant, ISF grant (No. 1182/21), Minerva grant (No. 713237), Hydrotronics (No. 873028) and the ERC-Cog (See-1D-Qmatter, No. 647413). T. S. acknowledges the support of the Natural Sciences and Engineering Research Council of Canada (NSERC), in particular the Discovery Grant (No. RGPIN-2020-05842), the Accelerator Supplement (No. RGPAS-2020-00060) and the Discovery Launch Supplement (No. DGECR-2020-00222). This research was enabled in part by support provided by Compute Canada. A. S. was supported by the ERC under the Horizon 2020 Research and Innovation programme (LEGOTOP No. 788715), the DFG (CRC/Transregio 183, EI 519/7-1), and the ISF Quantum Science and Technology (2074/19).
Publisher Copyright:
© 2022 American Physical Society.
All Science Journal Classification (ASJC) codes
- General Physics and Astronomy