Electronic specific heat and low energy quasiparticle excitations in superconducting state of $L{a}_{2-x}S{r}_{x}Cu{O}_4$ single crystals

Abstract

Low temperature specific heat has been measured and extensively analyzed on a series of $L{a}_{2-x}S{r}_{x}Cu{O}_4$ single crystals from underdoped to overdoped regime. From these data the quasiparticle density of states (DOS) in the mixed state is derived and compared to the predicted scaling law $C_{vol}/T\sqrt{H}=f(T/\sqrt{H})$ of d-wave superconductivity. It is found that the scaling law can be nicely followed by the optimally doped sample (x=0.15) in quite wide region of ($T/\sqrt{H}\le 8K/\sqrt{T}$). However, the region for this scaling becomes smaller and smaller towards more underdoped region: a clear trend can be seen for samples from x=0.15 to 0.069. Therefore, generally speaking, the scaling quality becomes worse on the underdoped samples in terms of scalable region of $T/\sqrt{H}$. This feature in the underdoped region is explained as due to the low energy excitations from a second order (for example, anti-ferromagnetic correlation, d-density wave, spin density wave or charge density wave order) that may co-exist or compete with superconductivity. Surprisingly, deviations from the d-wave scaling law have also been found for the overdoped sample (x=0.22). While the scaling law is reconciled for the overdoped sample when the core size effect is taken into account. An important discovery of present work is that the zero-temperature data follow the Volovik's relation $\Delta \gamma (T=0)=A\sqrt{H}$ quite well for all samples investigated here although the applicability of the d-wave scaling law to the data at finite temperatures varies with doped hole concentration. Finally we present the doping dependence of some parameters, such as, the residual linear term ${\gamma }_0$, the $\alpha$ value, etc. ...

15 pages, 24 figures

References in corpus (36)

• Hidden Order in the Cuprates
• A Four-Unit-Cell Periodic Pattern of Quasiparticle States Surrounding Vortex Cores in Bi2Sr2CaCu2O8+d
• Imaging the granular structure of high-Tc superconductivity in underdoped Bi2Sr2CaCu2O8+x
• Antiferromagnetic Order Induced by an Applied Magnetic Field in a High-Temperature Superconductor
• Superconducting Vortex with Antiferromagnetic Core
• STM Studies of the Electronic Structure of Vortex Cores in Bi2Sr2CaCu2O8+d
• Magnetic Induction of d + i d Order in High-Tc Superconductors
• Spin ordering quantum transitions of superconductors in a magnetic field
• Heat Transport in a Strongly Overdoped Cuprate: Fermi Liquid and Pure d-wave BCS Superconductor
• Density Wave States of Non-Zero Angular Momentum
• Mixed-State Quasiparticle Spectrum for d-wave Superconductors
• Self-consistent electronic structure of a $d_{x^2-y^2}$ and a $d_{x^2-y^2}+i{d}_{xy}$ vortex
• Charge order, superconductivity, and a global phase diagram of doped antiferromagnets
• Bose-Einstein to BCS Crossover Picture for High-T_c Cuprates
• Competing orders in a magnetic field: spin and charge order in the cuprate superconductors
• Scaling of the quasiparticle spectrum for d-wave superconductors
• Transport Properties of d-Wave Superconductors in the Vortex State
• Observation of d-wave scaling relations in the mixed-state specific heat of YBa2Cu3O7
• Evidence of Doping-Dependent Pairing Symmetry in Cuprate Superconductors
• Vortex Contribution to Specific Heat of Dirty $d$-Wave Superconductors: Breakdown of Scaling
• Quasiparticle States at a d-Wave Vortex Core in High-Tc Superconductors: Induction of Local Spin Density Wave Order
• Singularity of the Vortex Density of States in d-wave Superconductors
• Bond operator theory of doped antiferromagnets: from Mott insulators with bond-centered charge order, to superconductors with nodal fermions
• Fermionic entropy of the vortex state in d-wave superconductors
• Magnetic field induced charge and spin instabilities in cuprate superconductors
• Magnetic-Field-Induced Localization of Quasiparticles in Underdoped La${}_{2-x}$Sr${}_x$CuO${}_4$ Single Crystals
• Thermodynamics of d-wave superconductors in a magnetic field
• Hole Doping Dependence of the Coherence Length in $L{a}_{2-x}S{r}_{x}Cu{O}_4$ Thin Films
• Theory of Magnetic Field Induced Spin Density Wave in High Temperature Superconductors
• Delocalized Quasiparticles in the Vortex State of an Overdoped High-Tc Superconductor Probed by 63Cu NMR
• The same superconducting criticality for underdoped and overdoped La_{2-x}Sr_xCuO_4 single crystals
• Numerical Study of Transition to Stripe Phases in High Temperature Superconductors Under a Strong Magnetic Field
• On Measuring Condensate Fraction in Superconductors
• Microscopic phase separation in the overdoped region of high-Tc cuprate superconductors
• Comment on "Scaling of the quasiparticle spectrum for d-wave superconductors"
• O(4)-Invariant Formulation of the Nodal Liquid

Cited by in corpus (38)

• Fully Gapped Superconducting State Based on a High Normal State Quasiparticle Density of States in Ba${}_{0.6}$K${}_{0.4}$Fe${}_2$As${}_2$ Single Crystals
• Low temperature specific heat of the hole-doped Ba_{0.6}K_{0.4}Fe_2As_2 single crystals and electron-doped SmFeAsO_{0.9}F_{0.1} samples
• A review of two-band superconductivity: materials and effects on the thermodynamic and reversible mixed-state properties
• Weak coupling d-wave BCS superconductivity and unpaired electrons in overdoped La_{2-x}Sr_{x}CuO_{4} single crystals
• Ca${}_3$Ir${}_4$Sn${}_{13}$: A weakly correlated nodeless superconductor
• Nodeless superconductivity in K${}_x$Fe${}_{2-y}$Se${}_2$ single crystals revealed by low temperature specific heat
• Distinct Pairing Symmetries in $N{d}_{1.85}C{e}_{0.15}Cu{O}_{4-y}$ and $L{a}_{1.89}S{r}_{0.11}Cu{O}_4$ Single Crystals: Evidence from Comparative Tunnelling Measurements
• Evidence for multiple gaps in specific heat of LiFeAs crystals
• Doping dependence of the upper critical field in La_{2-x}Sr_xCuO_4 from specific heat
• Pseudogap, Superconducting Energy Scale, and Fermi Arcs in Underdoped Cuprate Superconductors
• Directly visualizing the sign change of d-wave superconducting gap in Bi2Sr2CaCu2O8+δ by phase-referenced quasiparticle interference
• Enhanced $T_c$ and multiband superconductivity in the fully-gapped ReBe${}_{22}$ superconductor
• Possible nodeless superconductivity in the noncentrosymmetric superconductor Mg_(12-delta)Ir_19B_16
• Nodeless Superconductivity in the Noncentrosymmetric Superconductor $M{g}_{10}I{r}_{19}{B}_{16}$
• Low temperature specific heat of 12442-type KCa_2Fe_4As_4F_2 single crystals
• Light-induced nonequilibrium response of the superconducting cuprate La${}_{2-x}$Sr${}_x$CuO${}_4$
• Theory of High-Tc Superconductivity: Accurate Predictions of Tc
• Theory of High-Tc Superconductivity: Transition Temperature
• Generalization of Anderson's Theorem for Disordered Superconductors
• Evidence for line nodes in the energy gap of the overdoped Ba(Fe${}_{1-x}$Co${}_x$)${}_2$As${}_2$ from low-temperature specific heat measurements
• Comment on "Low-temperature phonon thermal conductivity of single-crystalline Nd_{2}CuO_{4}: Effects of sample size and surface roughness" by Li et al.
• Real time measurement of the emergence of superconducting order in a high temperature superconductor
• Multigap superconductivity in the Mo${}_5$PB${}_2$ boron-phosphorus compound
• Multiple- to single-gap superconductivity crossover in Nb${}_5$Ir${}_{3-x}$Pt${}_x$O alloys
• Coexisting Holes and Electrons in High-Tc Materials: Implications from Normal State Transport
• Weak phase stiffness and nature of the quantum critical point in underdoped cuprates
• Magnetic-susceptibility and specific-heat studies on the inhomogeneity of superconductivity in the underdoped La_2-x_Sr_x_CuO_4_
• Two energy scales and close relationship between the pseudogap and superconductivity in underdoped cuprate superconductors
• Weak phase stiffness and mass divergence of superfluid in underdoped cuprates
• Determination of the superconducting gap in near optimally doped Bi_2Sr_{2-x}La_xCuO_{6+δ} (x ~ 0.4) from low-temperature specific heat
• Coherent topological defect dynamics and collective modes in superconductors and electronic crystals
• Specific Heat Investigation for Line Nodes in Heavily Overdoped Ba1-xKxFe2As2
• Multiple gaps revealed by low temperature specific heat in the 1111-type CaFe_{0.88}Co_{0.12}AsF single crystals
• Probing the superconducting pairing of the La${}_4$Be${}_{33}$Pt${}_{16}$ alloy via muon-spin spectroscopy
• Superconductor to metal transition in overdoped cuprates
• Normal charge densities in quantum critical superfluids
• Gap Structure of the Overdoped Iron-Pnictide Superconductor Ba(Fe${}_{0.942}$Ni${}_{0.058}$)${}_2$As${}_2$: A Low-Temperature Specific-Heat Study
• New pairing mechanism via chiral electron-hole condensation for non-BCS superconductivity