Photoinduced hole-doping effect in (Y0.5Ca0.5)Ba2Cu3Oδ films

Abstract

The persistent photoinduced changes in the critical temperature TC and the normal state conductivity of (Y0.5Ca0.5)Ba2Cu3Oδ thin films are studied. Previously such effects have been observed only in underdoped YBa2Cu3Oδ or YSrxBa2−xCu3Oδ, which always lead to the enhancement of both TC and conductivity. The current system can be doped from the underdoped regime to the overdoped regime by increasing its oxygen content. The photoinduced TC reduction in the overdoped films is observed. The simultaneous enhancement of conductivity is consistent with the interpretation that photoillumination always increases hole concentration in the “123” systems.

Modulation of Insulator-Metal Transition Temperature by Visible Light in La 7/8 Sr 1/8 MnO 3 Thin Film

“…[24−26] Persistent enhancement of both 𝑇 SC and conductivity induced by light illumination due to photoinduced hole-doping effect have been observed in YBa 2 Cu 3 O 𝑦 and (Y 0.5 Ca 0.5 )Ba 2 Cu 3 O 𝛿 films. [24,25] Based on the explanation of the photoinduced effect in high-𝑇 SC superconducting cuprates, we argue that the increase of charge carries not only decrease the resistance, both also shift the 𝑇 𝑃 to a higher temperature via photoinduced hole-doping effect in our case. In addition to enhancement of 𝑇 SC , photoinduced 𝑇 SC reduction has also been observed in the overdoped (Y 0.5 Ca 0.5 )Ba 2 Cu 3 O 𝛿 film obtained by varying its oxygen content.…”

“…In addition to enhancement of 𝑇 SC , photoinduced 𝑇 SC reduction has also been observed in the overdoped (Y 0.5 Ca 0.5 )Ba 2 Cu 3 O 𝛿 film obtained by varying its oxygen content. [25] This indicates that the photoinduced changes in the critical temperature 𝑇 SC rely on the relation between 𝑇 SC and the hole-doping level.…”