Josephson current and noise at a superconductor/quantum-spin-Hall-insulator/superconductor junction

By Liang Fu, C. L. Kane. 2008

660 citations recorded by the source corpus.

We study junctions between superconductors mediated by the edge states of a quantum-spin-Hall insulator. We show that such junctions exhibit a fractional Josephson effect, in which the current phase relation has a $4\ensuremath{\pi}$ rather than a $2\ensuremath{\pi}$ periodicity. This effect is a consequence of the conservation of fermion parity---the number of electron $\text{mod}\text{ }2$---in a superconducting junction and is closely related to the ${Z}_{2}$ topological structure of the quantum-spin-Hall insulator. Inelastic processes, which violate the conservation of fermion parity, lead to telegraph noise in the equilibrium supercurrent. We predict that the low-frequency noise due these processes diverges exponentially with temperature $T$ as $T\ensuremath{\rightarrow}0$. Possible experiments on HgCdTe quantum wells will be discussed.

Subfields: Atomic and Molecular Physics, and Optics, Condensed Matter Physics

View Paper: https://www.semanticscholar.org/paper/302bf4e9cafa0dce4d2ccafb06f49669acdf3aaa

How researchers see this paper

The researchers whose trusted networks rank it highest, strongest advocate first. Every researcher gets a different order.

In Atomic and Molecular Physics, and Optics

1. C. Beenakker
2. J. Alicea
3. Masatoshi Sato
4. Shoucheng Zhang
5. Xiao-Liang Qi
6. N. Lindner
7. C. Nayak
8. Erez Berg

In Condensed Matter Physics

1. C. Beenakker
2. J. Alicea
3. Shoucheng Zhang
4. Xiao-Liang Qi
5. Masatoshi Sato
6. A. Stern
7. C. Nayak
8. P. Fendley

Citations in the corpus

• Josephson radiation from gapless Andreev bound states in HgTe-based topological junctions (2016, background): “Coupling the topological edge channels of a 2D TI to a nearby conventional s-wave superconductor leads to the appearance of an induced p-wave superconducting phase [4].”
• Universal topological quantum computation from a superconductor/Abelian quantum Hall heterostructure (2013, background): “In this case the Cooper-paired regions constitute 1D topological super-conductors that produce a Majorana zero-mode exponentially bound to each domain wall [65].”
• InAs-Al hybrid devices passing the topological gap protocol (2022, background): “The corresponding two-dimensional topological superconducting state can occur in p + ip superconductors [57], at the surface of a topological insulator [60, 61], in ferromagnetic insulatorsemiconductor-superconductor heterostructures [10, 62– 66], and in s-wave superfluids of ultra-cold fermionic at”
• Topological insulators and superconductors (2010, methodology): “For a topological superconductor ring with Majorana fermions at both ends, the period of Josephson current is doubled, independent from the physical realization (Fu and Kane, 2009; Kitaev, 2001; Lutchynet al., 2010).”
• Search for Majorana Fermions in Superconductors (2011, background): “2), external tunneling events which change the quasiparticle parity (socalled quasiparticle poisoning) restore the conventional 2π-periodicity [19].”