Correlation between superconducting gap and pseudogap in high-{Tc} cuprates

Journal Article · Mon Nov 01 04:00:00 EST 1999 · Journal of Low Temperature Physics

DOI:https://doi.org/10.1023/A:1022509430952· OSTI ID:20012812

Ido, M; Momono, N; Oda, M

The authors studied the low-temperature energy gap 2{Delta}{sub o} on Bi{sub 2}Sr{sub 2}CaCu{sub 2}O{sub 8}+{delta} (Bi2212) and La{sub 2{minus}x}Sr{sub x}CuO{sub 4} (La214) systematically over a wide range of doping level p using STS, break junction tunneling spectroscopy, Raman scattering and low-T electronic specific heat data. They have also studied the electronic specific heat of La214 in the normal state at T {gt} {Tc}, and confirmed that pseudogap behavior appears at around T*, below which the in-plane resistivity {rho} and magnetic susceptibility {chi} tend to be slightly suppressed. Similar suppression appears in {rho} and {chi} of Bi2212 below the onset temperature of pseudogap T*. It is pointed out in the present study that 2{Delta}{sub o} is closely related to T* in both Bi2212 and La214 systems; T* {approximately} 2{Delta}{sub o}/4.3 k{sub B}. It is also pointed out that 2{Delta}{sub o} is in almost linear proportion to k{sub B}T{sub max}({much{underscore}lt}T*), where T{sub max} is the temperature exhibiting a broad peak in {chi}-T curves and k{sub B}T{sub max} can be considered to give a measure of the effective antiferromagnetic exchange energy J{sub eff}. The {alpha} factors in 2{Delta}{sub o} {approximately} {alpha}k{sub B}T{sub max} {approximately} {alpha}J{sub eff} are {approximately} 1 for La214 and {approximately} 2 for Bi2212, respectively. They also report that in both Bi2212 and La214 systems {Tc} roughly scales with p{Delta}{sub o} except in highly doped samples, where {Tc} {proportional{underscore}to} 2{Delta}{sub o}.

• Research Organization: Hokkaido Univ., Sapporo (JP)
• OSTI ID: 20012812
• Journal Information: Journal of Low Temperature Physics, Journal Name: Journal of Low Temperature Physics Journal Issue: 3-4 Vol. 117; ISSN JLTPAC; ISSN 0022-2291
• Country of Publication: United States
• Language: English

Related Subjects

36 MATERIALS SCIENCE
BISMUTH OXIDES
CALCIUM OXIDES
COPPER OXIDES
CORRELATIONS
ENERGY GAP
HIGH-TC SUPERCONDUCTORS
LANTHANUM OXIDES
MAGNETIC SUSCEPTIBILITY
SPECIFIC HEAT
STRONTIUM OXIDES
SUPERCONDUCTIVITY