Effect of pseudogap on electronic anisotropy in the strain dependence of the superconducting Tc of underdoped YBa2Cu3Oy

M. Frachet; Daniel J. Campbell; Anne Missiaen; S. Benhabib; Francis Laliberté; B. Borgnic; T. Loew; J. Porras; S. Nakata; B. Keimer; M. Le Tacon; Cyril Proust; I. Paul; David LeBoeuf

doi:10.1103/PhysRevB.105.045110

Effect of pseudogap on electronic anisotropy in the strain dependence of the superconducting Tc of underdoped YBa2Cu3Oy

M. Frachet, Daniel J. Campbell, Anne Missiaen, S. Benhabib, Francis Laliberté, B. Borgnic, T. Loew, J. Porras, S. Nakata, B. Keimer, M. Le Tacon, Cyril Proust, I. Paul, David LeBoeuf

DOI 10.1103/PhysRevB.105.045110 · Physical Review B

T1

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Abstract

For orthorhombic superconductors we define thermodynamic anisotropy N≡dTc/dε22−dTc/dε11 as the difference in how superconducting Tc varies with strains εii, i=(1,2), along the in-plane directions. We study the hole doping (p) dependence of N on detwinned single crystals of underdoped YBa2Cu3Oy (YBCO) using the ultrasound technique. While the structural orthorhombicity of YBCO reduces monotonically with decreasing doping over 0.065<p<0.16, we find that the thermodynamic anisotropy shows an intriguing enhancement at the intermediate doping level, which is of electronic origin. Our theoretical analysis shows that the enhancement of the electronic anisotropy can be related to the pseudogap potential in the electronic spectrum that itself increases when the Mott insulating state is approached. Our results imply that the pseudogap is controlled by a local energy scale that can be tuned by varying the nearest-neighbor Cu-Cu bond length. Our work opens the possibility to strain engineer the pseudogap potential to enhance the superconducting Tc.

Source-reported materials — not catalogue approval

Formula	Reported Tc (K)	Pressure (GPa)	Type
YBa2Cu3Oy Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	34	Pressure not reported	unknown
YBa2Cu3Oy Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	55.8	Pressure not reported	unknown
YBa2Cu3Oy Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	60	Pressure not reported	unknown
YBa2Cu3Oy Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	62.5	Pressure not reported	unknown
YBa2Cu3Oy Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	67.7	Pressure not reported	unknown
YBa2Cu3Oy Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	77	Pressure not reported	unknown
YBa2Cu3Oy Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	82	Pressure not reported	unknown
YBa2Cu3Oy Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	92.3	Pressure not reported	unknown
YBa2Cu3Oy Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	88.5	Pressure not reported	unknown
Bi2Sr2CaCu2O8+δ Archive — visibility unverified Source-occurrence policy only; no material identity or catalogue acceptance is inferred from the formula.	—	Pressure not reported	unknown