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Flip-flopping fractional flux quanta
1Institute of Information Technology, Rapid Single-Flux Quantum (RSFQ) Design Group, University of Technology Ilmenau, Post Office Box 100565, D-98684 Ilmenau, Germany. thomas.ortlepp@tu-ilmenau.de
Science (New York, N.Y.)
|April 22, 2006
Summary
High-critical temperature superconductors with d-wave symmetry enable superconducting rings with pi phase shifts. These rings controllably toggle fractional magnetic flux polarity in logic circuits, enhancing device performance.
Area of Science:
- Condensed Matter Physics
- Superconductivity
- Quantum Computing
Background:
- High-critical temperature superconductors exhibit d-wave pairing symmetry.
- Superconducting rings with pi phase shifts possess a twofold degenerate ground state.
- This ground state allows spontaneous generation of fractional magnetic flux quanta.
Purpose of the Study:
- To integrate pi phase-biased superconducting rings into a logic circuit (flip-flop).
- To demonstrate controllable toggling of fractional magnetic flux polarity using single flux quantum pulses.
- To explore the potential of these rings as natural two-state devices in rapid single flux quantum logic.
Main Methods:
- Fabrication of superconducting rings with built-in pi phase shifts.
- Incorporation of these rings into a flip-flop logic circuit.
- Application of single flux quantum pulses to control flux polarity.
Main Results:
- Demonstrated controllable toggling of fractional magnetic flux polarity.
- Successfully integrated pi phase-biased rings into a functional flip-flop circuit.
- Observed the spontaneous generation of up or down polarity fractional magnetic flux quanta.
Conclusions:
- Pi phase-biased superconducting rings can be controllably manipulated in logic circuits.
- Integration into rapid single flux quantum logic offers advantages like reduced bias current needs, improved symmetry, and enhanced operation margins.
- These rings show promise as efficient two-state devices for quantum information processing.
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