Selection rules for Cooper pairing in two-dimensional interfaces and sheets

Abstract

Thin sheets deposited on a substrate and interfaces of correlated materials offer a plethora of routes towards the realization of exotic phases of matter. In these systems, inversion symmetry is broken which strongly affects the properties of possible instabilities -- in particular in the superconducting channel. By combining symmetry and energetic arguments, we derive general and experimentally accessible selection rules for Cooper instabilities in noncentrosymmetric systems which yield necessary and sufficient conditions for spontaneous time-reversal-symmetry breaking at the superconducting transition and constrain the orientation of the triplet vector. We discuss in detail the implications for various different materials. For instance, we conclude that the pairing state in thin layers of Sr${}_2$RuO${}_4$ must, as opposed to its bulk superconducting state, preserve time-reversal symmetry with its triplet vector being parallel to the plane of the system. All pairing states of this system allowed by the selection rules are predicted to display topological Majorana modes at dislocations or at the edge of the system. Applying our results to the LaAlO${}_3$/SrTiO${}_3$ heterostructures, we find that while the condensates of the (001) and (110) oriented interfaces must be time-reversal symmetric, spontaneous time-reversal-symmetry breaking can only occur for the less studied (111) interface. We also discuss the consequences for thin layers of URu${}_2$Si${}_2$ and UPt${}_3$ as well as for single-layer FeSe. On a more general level, our considerations might serve as a design principle in the search for time-reversal-symmetry-breaking superconductivity in the absence of external magnetic fields.

12 pages, 3 figures

References in corpus (15)

• Electric Field Control of the LaAlO${}_3$/SrTiO${}_3$ Interface Ground State
• Topological Defects and Gapless Modes in Insulators and Superconductors
• Superconductivity protected by spin-valley locking in ion-gated MoS2
• High Resolution Polar Kerr Effect Measurements of Sr2RuO4: Evidence for Broken Time Reversal Symmetry in the Superconducting State
• Helical Metal Inside a Topological Band Insulator
• Observation of broken time-reversal symmetry in the heavy fermion superconductor UPt${}_3$
• Odd-parity topological superconductor with nematic order: Application to CuxBi2Se3
• High mobility conduction at (110) and (111) LaAlO3/SrTiO3 interfaces
• Evidence for broken time-reversal symmetry in the superconducting phase of URu${}_2$Si${}_2$
• Topological superconductivity and unconventional pairing in oxide interfaces
• Pairing symmetry and dominant band in Sr2RuO4
• Order parameter in superconductors with non-degenerate bands
• Mechanism, time-reversal symmetry and topology of superconductivity in noncentrosymmetric systems
• Symmetry and topology of two-dimensional noncentrosymmetric superconductors
• Enhancing triplet superconductivity by the proximity to a singlet superconductor in oxide heterostructures

Cited by in corpus (28)

• Discovery of two-dimensional anisotropic superconductivity at KTaO${}_3$ (111) interfaces
• Two-dimensional superconductivity at the surfaces of KTaO3 gated with ionic liquid
• Theory of zero-field superconducting diode effect in twisted trilayer graphene
• Superconductivity, correlated insulators, and Wess-Zumino-Witten terms in twisted bilayer graphene
• Superconductivity and Local Inversion-Symmetry Breaking
• Two-dimensional superconductivity at the (111)LaAlO${}_3$/SrTiO${}_3$ interface
• Tailoring $T_c$ by symmetry principles: The concept of Superconducting Fitness
• Crystalline Nodal Topological Superconductivity and Bogolyubov Fermi Surfaces in Monolayer NbSe${}_2$
• Link between the Superconducting Dome and Spin-Orbit Interaction in the (111) LaAlO${}_3$/SrTiO${}_3$ Interface
• Pairing in graphene-based moiré superlattices
• Time-reversal-symmetry breaking and unconventional pairing in the noncentrosymmetric superconductor La${}_7$Rh${}_3$
• Nodal band-off-diagonal superconductivity in twisted graphene superlattices
• Electron irradiation effects on superconductivity in PdTe${}_2$: an application of a generalized Anderson theorem
• Time-reversal symmetry breaking and multigap superconductivity in the noncentrosymmetric superconductor La${}_7$Ni${}_3$
• Ultrathin Films of Superconducting Metals as a Platform for Topological Superconductivity
• Symmetry and correlation effects on band structure explain the anomalous transport properties of (111) LaAlO${}_3$/SrTiO${}_3$
• Magnetoresistance in the superconducting state at the (111) LaAlO${}_3$/SrTiO${}_3$ interface
• Chiral Superconductivity in UTe${}_2$ via Emergent $C_4$ Symmetry and Spin Orbit Coupling
• Chiral Superconductivity in Thin Films of doped Bi${}_2$Se${}_3$
• Adatom engineering magnetic order in superconductors: Applications to altermagnetic superconductivity
• Anomalous Enhancement of Upper Critical Field in Sr2RuO4 Thin Films
• Superconductivity and Frozen Electronic States at the (111) LaAlO${}_3$/SrTiO${}_3$ Interface
• Signatures of Electronic Nematicity in (111) LaAlO${}_3$/SrTiO${}_3$ Interfaces
• Inter-orbital Cooper pairing at finite energies in Rashba surface states
• Identification of Spin-Triplet Superconductivity through a Helical-Chiral Phase Transition in Sr${}_2$RuO${}_4$ Thin-Films
• Friedel oscillations and chiral superconductivity in monolayer NbSe${}_2$
• The role of electromagnetic gauge-field fluctuations in the selection between chiral and nematic superconductivity
• Surface chiral superconductivity in odd-parity nematic superconductors with magnetic impurities