Ubiquitous V-shape density of states in mixed state of clean limit type II superconductors; STM experiment and theory

Abstract

It is demonstrated theoretically and experimentally that the low energy density of states $N(E)$ is described by a singular V-shape form $N(E)=N_0(H)+\alpha |E|+O(E^2)$ for all clean superconductors in a vortex state, irrespective of the underlying gap structure. The linear term $\alpha |E|$ which has been not recognized so far is obtained by exactly evaluating the vortex contribution. Based on microscopic Eilenberger theory $N(E)$ is evaluated for isotropic gap, line and point node gaps to yield a V-shape $N(E)$. STS-STM experiments on NbSe${}_2$ and YNi${}_2$B${}_2$C give direct evidence for this. We provide arguments on significance of this finding and on relevance to other experiments.

5 pages, 4 figures

References in corpus (11)

• Vortices and Superfluidity in a Strongly Interacting Fermi Gas
• Field dependence of the vortex structure in d-wave and s-wave superconductors
• Scaling of the quasiparticle spectrum for d-wave superconductors
• Determination of the Superconducting Gap Structure in All Bands of the Spin-Triplet Superconductor Sr2RuO4
• Quasiparticle Density of States of Clean and Dirty s-Wave Superconductors in the Vortex State
• Field dependence of the zero energy density of states around vortices in an anisotropic gap superconductor
• Star-shaped Local Density of States around Vortices in a Type II Superconductor
• Theory of vortex excitation imaging via an NMR relaxation measurement
• Site-selective nuclear magnetic relaxation time in a superconducting vortex state
• Nonlinear response and scaling law in the vortex state of d-wave superconductors
• Specific heat and low-lying excitations in the mixed state for a type II superconductor

Cited by in corpus (12)

• Superconducting density of states and vortex cores of 2H-NbS2
• Imaging superconducting vortex core and lattice with the scanning tunneling microscope
• Field dependence of the vortex core size probed by STM
• Inherent spin density wave instability by vortices in superconductors with strong Pauli effects
• Tunneling into the vortex state of NbSe${}_2$ with van der Waals junctions
• Positions of Point-Nodes in Borocarbide Superconductor YNi2B2C
• Scanning tunnelling spectroscopy of the vortex state in NbSe2 using a superconducting tip
• FeTe${}_{0.55}$Se${}_{0.45}$ van der Waals Tunneling Devices
• Superconductivity in graphene stacks: from the bilayer to graphite
• Theoretical studies for identifying horizontal line nodes via angle-resolved density of states measurements ---Application to Sr${}_2$RuO${}_4$---
• Exotic heavy fermion superconductivity in atomically thin CeCoIn${}_5$ films
• Hard superconducting gap and vortex-state spectroscopy in NbSe${}_2$ van der Waals tunnel junctions