Higher-order topological phases for time-reversal-symmetry breaking superconductivity in UTe${}_2$

Abstract

The recent discovery of heavy-fermion superconductor UTe${}_2$ has broadened the possibility of realizing exotic time-reversal-symmetry-breaking superconductivity. However, a comprehensive understanding of the topological phases in the superconducting states of UTe${}_2$ is still lacking. Here, we present an exhaustive classification of topological phases for all time-reversal symmetry breaking pairing symmetries of UTe${}_2$. Using the K theoretical classification approach, we uncover that 25 out of 36 possible pairing states are classified as higher-order topological phases, with some demonstrating hybrid-order topology through an intricate interplay of hinge and corner states. Furthermore, under the weak-coupling condition of the pair potentials, the possible pairing symmetries are constrained to $B_{ju}+i{B}_{ku}$, $A_u+i{B}_{ju}$, and $B_{jg}+i{A}_u$ ($j,k=1,2,3$; $j\ne k$), where these symbols denote the irreducible representations of the point group $D_{2h}$. For these pairing states, the topological invariants are related to the Fermi surface topology via the Fermi-surface formula, enabling us to systematically diagnose higher-order topological phases. Using a tight-binding model, we demonstrate the higher-order topological phases of the mixed-parity $A_u+i{B}_{1g}$ superconductors, where the second-order and hybrid-order topological phases emerge as the number of Fermi surfaces enclosing the time-reversal invariant momentum evolves from two to four. The findings suggest that UTe${}_2$ serves as a compelling platform for exploring higher-order topological superconductors with diverse topological surface states.

26 pages, 7 figures

References in corpus (45)

• Non-Abelian Anyons and Topological Quantum Computation
• Topological Defects and Gapless Modes in Insulators and Superconductors
• Topology of crystalline insulators and superconductors
• Double crystallographic groups and their representations on the Bilbao Crystallographic Server
• Unconventional Superconductivity in Heavy Fermion UTe2
• Unconventional Superconductivity in UTe2
• Topological properties of spin-triplet superconductors and the Fermi surface topology in the normal state
• Multiple Superconducting Phases and Unusual Enhancement of the Upper Critical Field in UTe2
• Topological Blount's theorem of odd-parity superconductors
• Low energy band structure and symmetries of UTe2 from angle resolved photoemission spectroscopy
• Single-component superconducting state in UTe2 at 2 K
• First Observation of de Haas-van Alphen Effect and Fermi Surfaces in Unconventional Superconductor UTe2
• Higher-order topological phases on fractal lattices
• Large Reduction in the $a$-axis Knight Shift on UTe${}_2$ with $T_{\mathrm{c}}$ = 2.1 K
• Chiral superconductivity in UTe2 probed by anisotropic low-energy excitations
• Spatially inhomogeneous superconductivity in UTe2
• Three-Dimensional Majorana Fermions in Chiral Superconductors
• Single-Component Superconductivity in UTe${}_2$ at Ambient Pressure
• The fate of time-reversal symmetry breaking in UTe2
• Revealing a 3D Fermi Surface Pocket and Electron-Hole Tunneling in UTe${}_2$ with Quantum Oscillations
• Fully gapped pairing state in spin-triplet superconductor UTe${}_2$
• Magnetic Properties under Pressure in Novel Spin-Triplet Superconductor UTe2
• Change of superconducting character in UTe2induced by magnetic field
• Anapole superconductivity from $\mathcal{P}\mathcal{T}$-symmetric mixed-parity interband pairing
• Field-Induced Superconductivity near the Superconducting Critical Pressure in UTe2
• Quantum-geometry-induced anapole superconductivity
• Superconducting-Spin Reorientation in Spin-Triplet Multiple Superconducting Phases of UTe2
• Quantum interference between quasi-2D Fermi surface sheets in UTe2
• Anisotropic magnetic responses of topological crystalline superconductors
• Thermodynamic and electrical transport properties of UTe${}_2$ under uniaxial stress
• Magnetic reshuffling and feedback on superconductivity in UTe2 under pressure
• Possible Realization of Topological Crystalline Superconductivity with Time-Reversal Symmetry in UTe2
• Pairing symmetries of multiple superconducting phases in UTe2: Competition between ferromagnetic and antiferromagnetic fluctuations
• Higher-order topological superconductors from Weyl semimetals
• Hybrid-order topological odd-parity superconductors via Floquet engineering
• Higher-order topological semimetals and nodal superconductors with an order-two crystalline symmetry
• Thermodynamic transitions and topology of spin-triplet superconductivity: Application to UTe${}_2$
• Intrinsic Anomalous Thermal Hall Effect in the Unconventional Superconductor UTe2
• Incommensurate antiferromagnetism in UTe2 under pressure
• Electric Multipoles of Double Majorana Kramers Pairs
• Anisotropic paramagnetic response of topological Majorana surface states in the superconductor ${\text{UTe}}_2$
• Majorana multipole response with magnetic point group symmetry
• Majorana Spin Current Generation by Dynamic Strain
• Nuclear spin relaxation rate of nonunitary Dirac and Weyl superconductors
• Revealing isotropic abundant low-energy excitations in UTe${}_2$ through complex microwave surface impedance

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