Buried Dirac points in quantum spin Hall insulators: Implications for Majorana Kramers pair-based quantum computing
arXiv:2409.19052 · doi:10.1103/tw65-82r9
Abstract
For heterostructures formed by a quantum spin Hall insulator (QSHI) placed in proximity to a superconductor (SC), no external magnetic field is necessary to drive the system into a phase supporting topological superconductivity with Majorana zero energy states, making them very attractive for the realization of non-Abelian states and fault-tolerant qubits. Despite considerable work investigating QSHI edge states, there is still an open question about their resilience to large magnetic fields and the implication of such resilience for the formation of a quasi-1D topological superconducting state. In this work, we investigate the transport properties of helical edge states in a QSHI-SC junction formed by a InAs/GaSb (15nm/5nm) double quantum well and a superconducting tantalum (Ta) constriction. We observe a robust conductance plateau up to 2 T, signaling resilient edge state transport. Such resilience is consistent with the Dirac point for the edge states being buried in the bulk valence band. Using a modified Landauer-Buttiker analysis, we find that the conductance is consistent with 98% Andreev reflection probability owing to the high transparency of the InAs/GaSb-Ta interface. We further theoretically show that a buried Dirac point does not affect the robustness of the quasi-1D topological superconducting phase, and favors the hybridization of Majorana Kramer pairs and fermionic modes in the QSHI resulting in extended MKP states, highlighting the subtle role of buried Dirac points in probing MKPs.
17 pages, 20 figures, and 2 tables
References in corpus (62)
- Topological Insulators
- Topological insulators and superconductors
- Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
- Non-Abelian Anyons and Topological Quantum Computation
- Topological Order and the Quantum Spin Hall Effect
- Superconducting proximity effect and Majorana fermions at the surface of a topological insulator
- Unpaired Majorana fermions in quantum wires
- Majorana Fermions and a Topological Phase Transition in Semiconductor-Superconductor Heterostructures
- Helical liquids and Majorana bound states in quantum wires
- New directions in the pursuit of Majorana fermions in solid state systems
- Observation of Majorana Fermions in Ferromagnetic Atomic Chains on a Superconductor
- Kwant: a software package for quantum transport
- Josephson Current and Noise at a Superconductor-Quantum Spin Hall Insulator-Superconductor Junction
- Evidence for Helical Edge Modes in Inverted InAs/GaSb Quantum Wells
- Topological Defects and Gapless Modes in Insulators and Superconductors
- Quantum Spin Hall Effect in Inverted Type II Semiconductors
- Majorana fermions in chains of magnetic atoms on a superconductor
- Manipulation of Majorana fermion, Andreev reflection and Josephson current on topological insulators
- Observation of Quantum Spin Hall States in InAs/GaSb Bilayers under Broken Time-Reversal Symmetry
- Near-zero-energy end states in topologically trivial spin-orbit coupled superconducting nanowires with a smooth confinement
- Universal topological quantum computation from a superconductor/Abelian quantum Hall heterostructure
- Zero-bias anomaly in a nanowire quantum dot coupled to superconductors
- Time Reversal Invariant Topological Superconductivity and Majorana Kramers Pairs
- Topological Superconductivity in a Planar Josephson Junction
- Edge-mode Superconductivity in a Two Dimensional Topological Insulator
- Two-dimensional platform for networks of Majorana bound states
- Reproducing topological properties with quasi-Majorana states
- InAs-Al Hybrid Devices Passing the Topological Gap Protocol
- Gate-Tuned Spontaneous Exciton Insulator in Double-Quantum Wells
- Inducing Superconducting Correlation in Quantum Hall Edge States
- Zero-energy Andreev bound states from quantum dots in proximitized Rashba nanowires
- Ubiquitous non-Majorana Zero-Bias Conductance Peaks in Nanowire Devices
- Nontopological zero-bias peaks in full-shell nanowires induced by flux tunable Andreev states
- Supercurrent detection of topologically trivial zero-energy states in nanowire junctions
- Edge Transport in the Trivial Phase of InAs/GaSb
- Decaying spectral oscillations in a Majorana wire with finite coherence length
- Interplay of exciton condensation and quantum spin Hall effect in InAs/GaSb bilayers
- Exotic circuit elements from zero-modes in hybrid superconductor/quantum Hall systems
- Majorana Zero Modes in Graphene
- Zero-energy pinning of topologically-trivial bound states in multi-band semiconductor-superconductor nanowires
- Interference of chiral Andreev edge states
- Local and non-local quantum transport due to Andreev bound states in finite Rashba nanowires with superconducting and normal sections
- Andreev reflection in the fractional quantum Hall state
- Insulating state and giant non-local response in an InAs/GaSb quantum well in the quantum Hall regime
- Non-local transport via edge-states in InAs/GaSb coupled quantum wells
- Decays of Majorana or Andreev oscillations induced by steplike spin-orbit coupling
- Induced superconducting pairing in integer quantum Hall edge states
- Detection of Majorana Kramers pairs using a quantum point contact
- Realistic picture of helical edge states in HgTe quantum wells
- Induced superconducting correlations in the quantum anomalous Hall insulator
- Robust Helical Edge Transport in Quantum Spin Hall Quantum Wells
- Quantum Computing with Majorana Kramers Pairs
- Conductance feature smearing and anisotropic suppression of induced superconductivity in a Majorana nanowire
- Hidden edge Dirac point and robust quantum edge transport in InAs/GaSb quantum wells
- Progress in superconductor-semiconductor topological Josephson junctions
- Luttinger liquid in contact with a Kramers pair of Majorana bound states
- Chaotic Quantum Transport near the Charge Neutrality Point in Inverted Type-II InAs/GaSb Field-Effect Transistors
- Giant supercurrent states in a superconductor-InAs/GaSb-superconductor junction
- Andreev reflection of quantum Hall states through a quantum point contact
- Majorana bound states in topological insulators with hidden Dirac points
- SU(4) Symmetry Breaking and Induced Superconductivity in Graphene Quantum Hall Edges
- Epitaxial aluminum layer on antimonide heterostructures for exploring Josephson junction effects