Single-electron transistors in electromagnetic environments (2003)
The current-voltage (I-V) characteristics of single-electron transistors (SETs) have been measured in various electromagnetic environments. Some SETs were biased with one-dimensional arrays of dc...
Circuit with small-capacitance high-quality Nb Josephson junctions (2003)
Watanabe, Michio, Nakamura, Yasunobu, Tsai, Jaw-Shen
We have developed a fabrication process for nanoscale tunnel junctions which includes focused-ion-beam etching from different directions. By applying the process to a Nb/(Al-)Al_2O_3/Nb trilayer, we...
Quantum Effects in Small-Capacitance Single Josephson Junctions (2003)
Watanabe, Michio, Haviland, David B.
We have measured the current-voltage (I-V) characteristics of small-capacitance single Josephson junctions at low temperatures (T=0.02-0.6 K), where the strength of the coupling between the single...
Small-Capacitance Josephson Junctions: One-Dimensional Arrays and Single Junctions (2003)
Watanabe, Michio, Haviland, David B.
We review experiments on small-capacitance Josephson junctions. When the Josephson junction is fabricated in the configuration of dc superconducting quantum interference device (SQUID), the Josephson...
Superconducting SET with tunable electromagnetic environment (2002)
Watanabe, Michio, Ishibashi, Koji, Aoyagi, Yoshinobu
We have studied the environmental effect on superconducting single-electron transistors (S-SETs) by biasing S-SETs with arrays of small-capacitance dc SQUIDs, whose effective impedance can be varied...
Critical exponents for the metal-insulator transition of ^{70}Ge:Ga in magnetic fields (2002)
Watanabe, Michio, Itoh, Kohei M., Morishita, Masashi, Ootuka, Youiti, Haller, Eugene E.
We have measured the electrical conductivity of nominally uncompensated ^{70}Ge:Ga samples in magnetic fields up to B=8 T at low temperatures (T=0.05-0.5 K) in order to investigate the...
Coulomb Blockade and Coherent Single-Cooper-Pair Tunneling in Single Josephson Junctions (2001)
Watanabe, Michio, Haviland, David B.
We have measured the current-voltage characteristics of small-capacitance single Josephson junctions at low temperatures (T < 0.04 K), where the strength of the coupling between the single junction...
Metal-Insulator Transition in Homogeneously Doped Germanium (2000)
We have measured the electrical conductivity of Ge:Ga samples prepared by neutron-transmutation doping of isotopically enriched 70Ge single crystals in order to study the metal-insulator transition...
Magetoresistance of RuO_2-based resistance thermometers below 0.3 K (2000)
Watanabe, Michio, Morishita, Masashi, Ootuka, Youiti
We have determined the magnetoresistance of RuO_2-based resistors (Scientific Instruments RO-600) between 0.05 K and 0.3 K in magnetic fields up to 8 T. The magnetoresistance is negative around 0.5 T...
Watanabe, Michio, Itoh, Kohei M., Ootuka, Youiti, Haller, Eugene E.
We have determined the localization length \xi and the impurity dielectric susceptibility \chi_{\rm imp} as a function of Ga acceptor concentrations (N) in nominally uncompensated ^{70}Ge:Ga just...
Watanabe, Michio, Itoh, Kohei M., Ootuka, Youiti, Haller, Eugene E.
We have investigated the temperature dependence of the electrical conductivity sigma(N,B,T) of nominally uncompensated, neutron-transmutation-doped ^{70}Ge:Ga samples in magnetic fields up to B=8 T...
Watanabe, Michio, Ootuka, Youiti, Itoh, Kohei M., Haller, Eugene E.
We report the low temperature carrier transport properties of a series of nominally uncompensated neutron-transmutation doped (NTD) ^{70} Ge:Ga samples very close to the critical concentration N_c...
Economics of Environmental Management in a Spatially Heterogeneous River Basin
Michio Watanabe, Richard M. Adams, JunJie Wu
This article examines the allocative efficiency of water quality management activities to protect endangered salmonid species in a heterogeneous watershed in the Pacific Northwest. Using an...