Taro Itatani

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National Metrology Institute of Japan have been proposed and fabricated the quantized Hall resistance (QHR) array devices, and confirmed the performance with uncertainty of as low as 10<sup>-8</sup>. The new combinations of Hall bars have been designed ranging from 100 &#x03A9; to 1 M&#x03A9;. This new combinations realize the quantized resistance values(More)
We have developed a on-chip double-shielded quantum Hall device and a double-shielded chip-carrier. The device in conjunction with the carrier will realize impedance standard based on the quantum Hall effect. In this configuration, the Hall bar is covered by separated on-chip shields and shields of the chip carrier to retrieve the leakage current. In this(More)
We have realized a high-detection-efficiency photon number resolving detector at an operating wavelength of about 850 nm. The detector consists of a titanium superconducting transition edge sensor in an optical cavity, which is directly coupled to an optical fiber using an approximately 300-nm gap. The gap reduces the sensitive area and heat capacity of the(More)
Channel mobility &#x00B5;<inf>eff</inf> for InGaAs MISFETs is improved by using the (111)A surface orientation and (NH<inf>4</inf>)<inf>2</inf>S treatment. These &#x00B5;<inf>eff</inf> improvements are associated with negative shifts in V<inf>th</inf> and V<inf>fb</inf>. We propose that carrier scattering by fluctuated dipoles at the MIS interfaces(More)
A quantum Hall array resistance standard (QHARS) device with a nominal value close to 10 k&#x03A9; on the <i>i</i> = 2 plateau has been developed on a GaAs/AlGaAs heterosubstrate. This QHARS device consists of 266 Hall bar elements, and its nominal value has only 0.0342 &#x00D7; 10<sup>-6</sup> difference based on <i>R</i><sub>K-90</sub> ( = 25 812.807(More)
We propose a new design for a 10-<formula formulatype="inline"><tex Notation="TeX">$\hbox{k}\Omega$</tex></formula> quantized Hall resistance (QHR) array device. This design realizes quantized resistance values that approach decade values with fewer Hall bars. In this design, the 10-<formula formulatype="inline"><tex(More)
An experimental device of quantum Hall array resistance standards (QHARS) with a nominal value close to 10 k&#x2126; on the i = 2 plateau have been developed on a GaAs/AlGaAs hetero-substrate. This device consists of just 266 Hall bar elements that are connected by triple connection technique. Its nominal value has only 0.034 2 ppm differences from the(More)
This paper describes evolvable optical systems and their applications developed at the National Institute of Advanced Industrial Science and Technology(AIST) in Japan. Three evolvable optical systems are described: (1) an evolvable ber alignment system, (2) an evolvable interferometer system, and (3) an evolvable femtosecond laser system. As the(More)