Noise in the helical edge channel anisotropically coupled to a local spin
| Autor: | Nagaev, K. E., Remizov, S. V., Shapiro, D. S. |
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| Rok vydání: | 2018 |
| Předmět: | |
| Zdroj: | JETP Lett. 108, No. 10, 664 - 669 (2018) |
| Druh dokumentu: | Working Paper |
| DOI: | 10.1134/S002136401822006X |
| Popis: | We calculate the frequency-dependent shot noise in the edge states of a two-dimensional topological insulator coupled to a magnetic impurity with spin $S=1/2$ of arbitrary anisotropy. If the anisotropy is absent, the noise is purely thermal at low frequencies, but tends to the Poissonian noise of the full current $I$ at high frequencies. If the interaction only flips the impurity spin but conserves those of electrons, the noise at high voltages $eV\gg T$ is frequency-independent. Both the noise and the backscattering current $I_{bs}$ saturate at voltage-independent values. Finally, if the Hamiltonian contains all types of non-spin-conserving scattering, the noise at high voltages becomes frequency-dependent again. At low frequencies, its ratio to $2eI_{bs}$ is larger than 1 and may reach 2 in the limit $I_{bs}\to 0$. At high frequencies it tends to 1. Comment: 5 pages, 2 figs |
| Databáze: | arXiv |
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