Papers Published in Technical Journals and Conferences
Sub-THz RTD Oscillators Integrated with Planar Horn Antennas for Horizontal Radiation
K. Urayama, S. Suzuki, M. Asada, H. Sugiyama, and H. Yokoyama
Proc. of IRMMW-THz 2008, p. T5D42, Pasadena, CA, USA, 2008.
Fabrication and oscillation characteristics of sub-THz resonant tunneling diode (RTD) oscillators integrated with planar horn antennas for horizontal radiation are reported. The device consists of a GaInAs/AlAs RTD, a resonator, a waveguide, and a horn antenna on a semi-insulating InP substrate. Oscillation frequency of 455 GHz and horizontal output power of ~0.6 µW were observed. The output power is small at present because of small values of the peak-to-valley current ratio and the voltage width of the negative differential resistance region of the RTD.
Present Status and Prospects of H-terminated Diamond RF Power FETs
M. Kasu, K. Ueda, and K. Michal
NEW DIAMOND, Ohmsha, Vol. 25, No. 1, pp. 3–7, 2009.
Recent achievements of diamond radio-frequency power devices toward information technology systems are reviewed.
Frequency Switching with Bias Polarity in Resonant Tunneling Diodes Oscillating at Around 600 GHz
S. Suzuki, A. Teranishi, K. Hinata, M. Asada, H. Sugiyama, and H. Yokoyama
Proc. of OTST 2009, OSA, Vol. OTST2009, p. SuE1, Santa Barbara, USA.
We report resonant tunneling diode (RTD) oscillators which have two frequencies switched with bias polarity at around 600 GHz.
Cloning of qubits with both the cloned state and the state orthogonal to it as inputs
Phys. Rev. A, APS, Vol. 79, No. 3, pp. 032315-1–7, 2009.
A universal cloning machine is derived. The machine produces c clones of an unknown qubit from s identical replicas of the qubit and k identical replicas of its orthogonal qubit. For the standard cloning machine, i.e., k=0, the universal-not machine, s=0, and some other cases, the optimum machine is well known. The universal cloning machine derived in this paper gives clones whose fidelity is the same value as that for the optimum machine. In the case of sufficiently large c, we show that the clone fidelity generated by the cloning machine from s≠0 replicas and k≠0 orthogonal replicas is higher than that generated by the optimal cloning machine from s+k replicas in the case of s+k≤300.
Synthesis and properties of superconducting T'-R2CuO4