97 citations · 203 across the 7 of their papers we have counts for
9 papers
Macroscopic quantum tunneling in multigap superconducting Josephson junctions: Escape rate enhancement via quantum fluctuations of Josephson-Leggett mode
Yukihiro Ota, Masahiko Machida, Tomio Koyama
We theoretically study the macroscopic quantum tunneling (MQT) in a hetero Josephson junction formed by a conventional single-gap superconductor and a multi-gap one such as ${MgB}_…
Reply to the comment [arXiv:0903.5110] on "Mechanism of Terahertz Electromagnetic Emission from Intrinsic Josephson Junctions" [arXiv:0810.5268]
Masashi Tachiki, Tomio Koyama, Shouta Fukuya
We reply to the comment [arXiv:0903.5110] on our paper "Mechanism of Terahertz Electromagnetic Emission from Intrinsic Josephson Junctions" [arXiv:0810.5268].
Intergrain Josephson Currents in Multigap Superconductors: Microscopic Origin of Low Intergrain Critical Current and Its Recovery Potential in Iron-Pnictide Materials
Yukihiro Ota, Masahiko Machida, Tomio Koyama
We microscopically examine the intergrain Josephson current in iron-pnictide superconductors in order to solve the puzzle of why the intergrain current is much lower than the intra…
Theory of heterotic SIS Josephson junctions between single- and multi-gap superconductors
Yukihiro Ota, Masahiko Machida, Tomio Koyama +1
Using the functional integral method, we construct a theory of heterotic SIS Josephson junctions between single- and two-gap superconductors. The theory predicts the presence of in…
Mechanism of Terahertz Electromagnetic Wave Emission from Intrinsic Josephson Junctions
Masashi Tachiki, Shouta Fukuya, Tomio Koyama
Using a 3-D parallelepiped model of intrinsic Josephson junctions, we calculate the cavity resonance modes of Josephson plasma waves excited by external electric currents. The elec…
Theory for Photon-Assisted Macroscopic Quantum Tunneling in a Stack of Intrinsic Josephson Junctions
Masahiko Machida, Tomio Koyama
We propose a theory for photon-assisted macroscopic quantum tunneling (MQT) in a stack of capacitively-coupled intrinsic Josephson junctions in which the longitudinal Josephson pla…