Quantum phase slip interference device based on superconducting nanowire

We propose a transistor-like circuit including two serially connected segments of a narrow superconducting nanowire joint by a wider segment with a capacitively coupled gate in between. This circuit is made of amorphous NbSi film and embedded in a network of on-chip Cr microresistors ensuring a sufficiently high external electromagnetic impedance. Assuming a virtual regime of quantum phase slips (QPS)in two narrow segments of the wire, leading to quantum interference of voltages on these segments, this circuit is dual to the dc SQUID. Our samples demonstrated appreciable Coulomb blockade voltage (analog of critical current of the SQUIDs) and periodic modulation of this blockade by an electrostatic gate (analog of flux modulation in the SQUIDs). The model of this QPS transistor is discussed.Comment: 5 pages including 3 figures; in v2 the title was updated, typos were fixed and 4 references adde

Quantum Zeno effect with a superconducting qubit

Detailed schemes are investigated for experimental verification of Quantum Zeno effect with a superconducting qubit. A superconducting qubit is affected by a dephasing noise whose spectrum is 1/f, and so the decay process of a superconducting qubit shows a naturally non-exponential behavior due to an infinite correlation time of 1/f noise. Since projective measurements can easily influence the decay dynamics having such non-exponential feature, a superconducting qubit is a promising system to observe Quantum Zeno effect. We have studied how a sequence of projective measurements can change the dephasing process and also we have suggested experimental ways to observe Quantum Zeno effect with a superconducting qubit. It would be possible to demonstrate our prediction in the current technology

A space communication study Progress report, 15 Sep. 1966 - 15 Mar. 1967

Space communications studies of optimal signal reception, threshold extension, signal detection against noise, channel simulation, and synchronization technique

Analysis of an F.M. Discriminator with Fading Signal plus Additive Gaussian Noise

Fading signal plus additive Gaussian noise applied to frequency modulation discriminator for determining fading effects on threshol

A space communications study Status report, 15 Dec. 1968 - 15 Mar. 1969

Harmonic distortion in frequency demodulator using feedback, delta modulation, recursive signal processing techniques, and multipath fadin

A space communication study Final report, 15 Sep. 1967 - 15 Sep. 1968

Transmitting and receiving analog and digital signals through noisy media - space communications stud

An experimental investigation into the constant velocity water entry of wedge-shaped sections

Constant velocity water entry is important in understanding planing and slamming of marine vessels. A test rig has been developed that drives a wedge section with end plates down guides to enter the water vertically at near constant velocity. Entry force and velocity are measured. Analysis of the test data shows that the wetting factor is about 1.6 at low deadrise angles and reduces nearly linearly to 1.3 at 451 deadrise angle. The added mass increases quadratically with immersed depth until the chines become wetted. It then continues to increase at a reducing rate, reaching a maximum value between 20% and 80% greater than at chine immersion. The flow momentum drag coefficient is estimated from the results to be 0.78 at 51 deadrise angle reducing to 0.41 at 451 deadrise angles. Constant velocity exit tests show that the momentum of the added mass is expended in driving the water above the surface level and that exit forces are low and equivalent to a drag coefficient of about 1.0-1.3. Considerable dynamic noise limits the accuracy of the results, particularly after chine immersion

A comparative study of educational administration in Jamaica and in the United States of America.

Thesis (Ed.M.)--Boston Universit

A Space Communications Study Final Report, Sep. 15, 1965 - Sep. 15, 1966

Reception of frequency modulated signals passed through deterministic and random time-varying channel

A space communications study Final report, 15 Sep. 1968 - 15 Sep. 1969

Analog and digital signal reception problems through noisy channels, and computerized digital TV system for space communication