Regensburg 2007 – wissenschaftliches Programm

Bereiche | Tage | Auswahl | Suche | Downloads | Hilfe

TT: Fachverband Tiefe Temperaturen

TT 28: Transport - Poster Session

TT 28.24: Poster

Donnerstag, 29. März 2007, 14:00–17:45, Poster A

Implementation of Two-Cell Flux Qubits — •Alexey Feofanov¹, Benjamin Hinrichs¹, Abdufarrukh Abdumalikov^1,2, and Alexey Ustinov¹ — ¹Physikalisches Institut III, Universität Erlangen-Nürnberg, Erlangen, Germany — ²Present address: Frontier Research System, RIKEN, Wako, Japan

The standard superconducting flux qubit first implemented at Delft [1] consists of a superconducting loop with three Josephson junctions, one of which is smaller than the other two, nominally identical junctions. This circuit features a double well potential at half frustration. Its limitation is that the barrier height cannot be changed without breaking the potential symmetry. An alternative device proposed by Yukon [2] is a two-cell flux qubit containing four Josephson junctions. The two-cell flux qubit can be made using identical junctions and features a double-well potential with orthogonal controls for the barrier height and the potential symmetry. We have designed and fabricated aluminum-based two-cell qubits with dc-SQUID readout and flux line controls. The useful feature of our latest two-cell qubit design is that it can be operated and read out at zero external magnetic field. Experiments to test these devices are currently on the way.

[1] I. Chiorescu, Y. Nakamura, C.J. Harmans, and J. E. Mooij, Science 299, 1869 (2003)

[2] S.P. Yukon, Physica C 368, 320 (2002)