Chiral Higgs Mode in Nematic Superconductors

Abstract

Nematic superconductivity with spontaneously broken rotation symmetry has recently been reported in doped topological insulators, $M_x$Bi${}_2$Se${}_3$ ($M$=Cu, Sr, Nb). Here we show that the electromagnetic (EM) response of these compounds provides a spectroscopy for bosonic excitations that reflect the pairing channel and the broken symmetries of the ground state. Using quasiclassical Keldysh theory, we find two characteristic bosonic modes in nematic superconductors: the nematicity mode and the chiral Higgs mode. The former corresponds to the vibrations of the nematic order parameter associated with broken crystal symmetry, while the latter represents the excitation of chiral Cooper pairs. The chiral Higgs mode softens at a critical doping, signaling a dynamical instability of the nematic state towards a new chiral ground state with broken time reversal and mirror symmetry. Evolution of the bosonic spectrum is directly captured by EM power absorption spectra. We also discuss contributions to the bosonic spectrum from sub-dominant pairing channels to the EM response.

15 pages, 7 figures

References in corpus (18)

• Odd-parity topological superconductor with nematic order: Application to CuxBi2Se3
• Thermodynamic properties of thin films of superfluid 3He-A
• Collective modes and electromagnetic response of a chiral superconductor
• Surface spectral function in the superconducting state of a topological insulator
• Gauge-invariant electromagnetic response of a chiral px+ipy superconductor
• Structural distortion behind the nematic superconductivity in Sr${}_x$Bi${}_2$Se${}_3$
• Superconducting doped topological materials
• High-pressure study of the basal-plane anisotropy of the upper critical field of the topological superconductor SrxBi2Se3
• Nanocalorimetric Evidence for Nematic Superconductivity in the Doped Topological Insulator Sr${}_{0.1}$Bi${}_2$Se${}_3$
• Quantum Oscillations in Cu${}_x$Bi${}_2$Se${}_3$ in High Magnetic Fields
• On Nambu's Fermion-Boson Relations for Superfluid ${}^3$He-B
• Nematic Superconductivity in Cu1.5(PbSe)5(Bi2Se3)6
• Spin triplet nematic pairing symmetry and superconducting double transition in U${}_{1-x}$Th${}_x$Be${}_{13}$
• Novel anisotropic spin singlet pairings in Cu${}_x$Bi${}_2$Se${}_3$ and Bi${}_2$Te${}_3$
• Effect of Fermi surface evolution on superconducting gap in superconducting topological insulator
• Chiral Superconductivity in Thin Films of doped Bi${}_2$Se${}_3$
• Anisotropy and Strong-Coupling Effects on the Collective Mode Spectrum of Chiral Superconductors: Application to Sr${}_2$RuO${}_4$
• Bosonic Surface States and Acoustic Spectroscopy of Confined Superfluid ${}^3$He-B

Cited by in corpus (23)

• Nematic superconductivity in doped Bi2Se3 topological superconductors
• Direction and symmetry transition of the vector order parameter in topological superconductors Cu${}_x$Bi${}_2$Se${}_3$
• Linear optical response from the odd parity Bardasis-Schrieffer mode in locally non-centrosymmetric superconductors
• Spin currents driven by the Higgs mode in magnetic superconductors
• Nematic superconductivity in topological insulators induced by hexagonal warping
• Signatures of the Higgs mode in transport through a normal-metal--superconductor junction
• Symmetries, Length Scales, Magnetic Response and Skyrmion Chains in Nematic Superconductors
• Magnetic response of nematic superconductors: skyrmion stripes and their signatures in muon spin relaxation experiments
• Spin-Nernst Effect in Time-Reversal-Invariant Topological Superconductors
• Spontaneous strain and magnetization in doped topological insulators with nematic and chiral superconductivity
• Surface Cooper pair spin waves in triplet superconductors
• The absence of Ginzburg-Landau mechanism for vestigial order in the normal phase above a two-component superconductor
• Lifshitz transition in dirty nematic superconductor
• On the Excitations of a Balian-Werthamer Superconductor
• Pauli paramagnetism of triplet Cooper pairs in a nematic superconductor
• Proximity-induced collective modes in an unconventional superconductor heterostructure
• Spin caloritronics as a probe of nonunitary superconductors
• Anomalous acoustoelectric effect induced by clapping modes in chiral superconductors
• Odd-frequency pairs and anomalous proximity effect in nematic and chiral states of superconducting topological insulators
• Anomalous Josephson Hall effect in doped topological insulators with the nematic superconductivity
• On the existence of nematic-superconducting states in the Ginzburg-Landau regime
• Hybrid collective excitations in topological superconductor/ferromagnetic insulator heterostructures
• Quasiclassical theory of vortex states in locally non-centrosymmetric superconductors: application to CeRh${}_2$As${}_2$