Eran Segev 2008-2009

Institution of PhD:
Technion - Israel Institute of Technology
Academic Discipline of PhD:
Electrical Engineering
PhD Advisor/s:
Dr. Eyal Buks
Dissertation Topic:
Metastability and Self-Oscillations in Superconducting Microwave Resonators Integrated with a dc-SQUID
Year Awarded PhD:
Institution of Postdoc:
California Institute of Technology
Present Institution:
Elbit Sytems

Eran Segev is an electrical engineer researching nanotechnology,specifically Quantum Nano-Mechanics. He chose nanotechnology because it is a revolutionary technological innovation that will create a massive change in all aspects of people’s lives. Quantum Nano-Mechanics is an emerging field in which the mechanical behavior of nano-scale systems in the quantum domain is studied. Eran explores ways to integrate nano-mechanical resonators and superconducting electrical resonators, in order to explore, for the first time, quantum phenomena in the former resonator. This research is at the cutting edge of building a first quantum computer. He is currently a postdoctoral fellow at the California Institute of Technology at the Kalvi Nanoscience Institute.

Eran wrote his PhD in the Technion – The Israel Institute of Technology, under the supervision of Prof. Eyal Buks. His thesis “Metastability and Self-Oscillations in Superconducting Microwave Resonators Integrated with a dc-SQUID” researched nonlinear effects in superconductors. The research studies thermal instability in superconducting stripline resonators working at gigahertz frequencies. We demonstrate how at a certain range of driving parameters, thermal instability creates extremely strong nonlinearity, which is manifested by self-sustained oscillations of the resonators at megahertz frequencies. This phenomenon is of a significant importance as it introduces an extreme nonlinearity, which is by far stronger than any other nonlinearity observed before in superconducting resonators. It results in a very high intermodulation gain, substantial noise squeezing, stochastic resonance, sensitive radiation detection, and strong coupling between different resonance modes. The source for the strong amplification along the thresholds of the self-oscillations is investigated and found to be a unique stochastic resonance between stable and unstable states of the resonator.

The research also studies metastable response of hysteretic nano-bridge based DC Superconducting QUantum Interference Devices (SQUIDs), subjected to an alternating biasing current, both theoretically and experimentally. SQUIDs based on nano-bridges constitute an emerging technology with a potential to out-perform traditional SQUIDs, based on superconducting-insulating-superconducting junctions, in terms of noise performance. The PhD theoretically analyzed stability zones of a highly hysteretic DC-SQUID in the plane of the bias current and magnetic flux control parameters, and found a periodic dissipative stability zone, which differs from the well known oscillatory zone that is found above the critical current of the SQUID. It was found that when such a SQUID is integrated in a resonator, thermal processes, which have similar characteristic rate as the resonance frequencies of the resonator, play an important role in the overall measured dynamics of the device.

Eran has published his findings in a variety of scientific journals including Physical Letters A and IEEE Transactions on Applied Superconductivity.