TopoInMulTermJJ · Multi-Terminal Josephson Junctions as a novel platform for high dimensional topological matter
Horizon 2020 — Marie Skłodowska-Curie Actions
- Duration
- 2017-10-01 → 2019-09-30
- EU contribution
- €173,076
- Participants
- 1
- Scheme
- MSCA-IF-EF-ST
Lines connect the coordinator with its partners.
Results in brief
Multi-Terminal Josephson Junctions as a novel platform for high dimensional topological matter
Josephson junctions host so-called Andreev bound states. As has been shown recently, the spectrum of Andreev bound states in an N-terminal Josephson junction as function of the superconducting phases can be viewed as a pseudo-bandstructure in N-1 dimension. This pseudo-bandstructure may have interesting topological properties. However, many questions concerning the characterization, classification, and manipulation of the topological states in multi-terminal Josephson junctions are still open. The objective of the project was to further explore this novel platform for topological matter.
Data: CORDIS, © European Union
Project objective
The spectrum of Andreev bound states in N-terminal Josephson Junctions (MulTJJ) may be viewed as a pseudo-bandstructure of N-1 dimension Bloch electrons. As we recently showed this pseudo-bandstructure may have interesting topological properties. (i) Topological transitions between ground states with different fermion parity may occur in a 3-terminal JJ upon varying the superconducting phases. (ii) In 4- or more terminal JJs, the pseudo-bandstructure may display Weyl nodes, that entail a non-trivial 1st Chern number in a 2D plane in the space of SC phase differences and lead to a measureable quantized transconductance under DC-bias voltage. However, questions concerning how to characterize, classify, and manipulate the topological states in MulTJJ are still open. The aim of this proposal is to continue to study this unexplored novel platform of topological matters. We start to study approaches to measure and manipulate topological states of MulTJJ in several more complicated nanostructures. These structures are interesting because topological properties are expected to be easily detected in similar experimental setups. We hope to observe exotic phenomena such as quantized transconductance, non-trivial modifications to the supercurrent and to waiting times due to the Berry phase. Moreover topological states are proposed to be manipulated in a gate-bias controllable dynamical process in a non-adiabatic driven quantum dot. We then propose to study the symmetry of MulTJJ in higher dimensions. In particular, we are interested in realizing a non-trivial 2nd Chern number, that would show up in the non-linear response of the system. For example we plan to study 6-/5-terminal JJ with/without time-reversal-symmetry in order to realize an analogue of the 4D quantum Hall effect. Finally, we seek to clarify the possible topological classes of MulTJJs. At the end of our research, we expect to obtain insights in understanding the topological properties of MulTJJs.
Original text from CORDIS.
Participants
- UNIVERSITE GRENOBLE ALPES · GrenobleCoordinatorFrance
Links
Data: CORDIS, © European Union