We report on doping and undoping experiments of terahertz (THz) emitting intrinsic Josephson junction stacks, where the change in charge carrier concentration is achieved by heavy current injection. The experiments were performed on stand-alone structures fabricated from a Bi2Sr2CaCu2O8+delta single crystal near optimal doping. The stacks contained about 930 intrinsic Josephson junctions. On purpose, the doping and undoping experiments were performed over only a modest range of charge carrier concentrations, changing the critical temperature of the stack by less than 1 K. We show that both undoping and doping is feasible also for the large intrinsic Josephson junction stacks used for THz generation. Even moderate changes in doping introduce large changes in the THz emission properties of the stacks. The highest emission power was achieved after doping a pristine sample.
C1 [Kizilaslan, O.; Rudau, F.; Wieland, R.; Hampp, J. S.; Koelle, D.; Kleiner, R.] Univ Tbingen, LISA, Physikal Inst & Ctr Quantum Sci CQ, D-72076 Tubingen, Germany.
[Kizilaslan, O.] Inonu Univ, Fac Engn, Dept Biomed Engn, TR-44280 Malatya, Malaysia.
[Zhou, X. J.; Ji, M.; Huang, Y.; Ishii, A.; Hatano, T.; Wang, H. B.] Natl Inst Mat Sci, Tsukuba, Ibaraki 3050047, Japan.
[Zhou, X. J.; Ji, M.; Huang, Y.; Hao, L. Y.; Wu, P. H.; Wang, H. B.] Nanjing Univ, Res Inst Superconductor Elect, Nanjing 210093, Peoples R China.
[Kiselev, O.; Kinev, N.; Koshelets, V. P.] Kotelnikov Inst Radio Engn & Elect, Moscow, Russia.
[Aksan, M. A.] Inonu Univ, Fac Arts & Sci, Dept Phys, TR-44280 Malatya, Turkey.