Spontaneous breakdown of topological protection in two dimensions

Abstract

Due to time-reversal symmetry (TRS), two dimensional topological insulators support counter-propagating helical edge modes. Here we show that, unlike the infinitely sharp edge potential utilized in traditional calculations, an experimentally more realistic smooth edge potential gives rise to edge reconstruction and, consequently, spontaneous TRS breaking. Such edge reconstruction may lead to breaking of the expected perfect conductance quantization, to a finite Hall resistance at zero magnetic field, and to a likely spin current. This calculation underpins the fragility of the topological protection in realistic systems, which is of crucial importance in proposed applications.

References in corpus (9)

• Quantum Spin Hall Effect and Topological Phase Transition in HgTe Quantum Wells
• Quantum Spin Hall Insulator State in HgTe Quantum Wells
• Nonlocal edge state transport in the quantum spin Hall state
• The Quantum Spin Hall Effect: Theory and Experiment
• The Helical Liquid and the Edge of Quantum Spin Hall Systems
• Observation of neutral modes in the fractional quantum Hall regime
• Resistance of helical edges formed in a semiconductor heterostructure
• Imaging fractional incompressible stripes in integer quantum Hall systems
• Non-Equilibrated Counter Propagating Edge Modes in the Fractional Quantum Hall Regime

Cited by in corpus (23)

• Exact solution of single impurity problem in non-reciprocal lattices: impurity induced size-dependent non-Hermitian skin effect
• Mesoscopic transport in two-dimensional topological insulators
• Two-dimensional topological insulator state in double HgTe quantum well
• Quantitative theory of backscattering in topological HgTe and (Hg,Mn)Te quantum wells: acceptor states, Kondo effect, precessional dephasing, and bound magnetic polaron
• Spin Mode-Switching at the Edge of a Quantum Hall System
• Edge stability and edge quantum criticality in 2D interacting topological insulators
• Magnetic field dependent equilibration of fractional quantum Hall edge modes
• Coherent-Incoherent Crossover of Charge and Neutral Mode Transport as Evidence for the Disorder-Dominated Fractional Edge Phase
• Breakdown of topological protection due to non-magnetic edge disorder in two-dimensional materials in the Quantum Spin Hall phase
• Finite frequency backscattering current noise at a helical edge
• Tomonaga Luttinger liquid in the topological edge channel of multilayer FeSe
• Reconstruction-Induced ${\phi }_0$ Josephson Effect in Quantum Spin Hall Constrictions
• Velocity and confinement of edge plasmons in HgTe-based 2D topological insulators
• Multiple Mechanisms for Emerging Conductance Plateaus in Fractional Quantum Hall States
• Tunable helical crystals
• Electronic thermal conductivity in 2D topological insulator in a HgTe quantum well
• Topological and magnetic properties of the interacting Bernevig-Hughes-Zhang model
• Experimentally Motivated Order of Length Scales Affect Shot Noise
• Edge Reconstruction and Emergent Neutral Modes in Integer and Fractional Quantum Hall Phases
• Effective Hamiltonian of topologically protected qubit in a helical crystal
• Sensing the binding and unbinding of anyons at impurities
• Strengthened correlations near [110] edges of $d$-wave superconductors in the t-J model with the Gutzwiller approximation
• Edge Reconstruction in a Quantum Spin Hall Insulator