Single- and double-qubit gates by manipulating fourfold degeneracy

T. Hakioğlu, J. Anderson, F. Wellstood

Research output: Contribution to journalArticlepeer-review

2 Citations (Scopus)


We propose a mechanism for single- and double-qubit state manipulations in quantum computation with an inseparable double-qubit structure. The principle is based on manipulating the degeneracy of the four energy levels. The degeneracy of levels is allowed to be fourfold, doubly degenerate in pairs and nondegenerate, and these configurations are tuned by two coupling parameters. The quantum gate operations are performed at the nondegenerate whereas the data are stored in the degenerate configurations. The fact that the center of the four energy levels is invariant at all parameter values is exploited, and this particularly increases the performance of the controlled operations. A particular realization of the proposed mechanism is suggested by using the recently proposed inductively coupled rf superconducting quantum interference device loops in the macroscopic quantum tunneling regime where the energy eigenlevels are directly connected with the measurable flux states. This very fact also allows precise read-in and read-out operations by measurement of the flux which can also be done by existing techniques. That other physical realizations of the mechanism than that examined here are likely to exist is also discussed briefly.

Original languageEnglish
Article number115324
Pages (from-to)1153241-1153248
Number of pages8
JournalPhysical Review B - Condensed Matter and Materials Physics
Issue number11
Publication statusPublished - 15 Sept 2002
Externally publishedYes


Dive into the research topics of 'Single- and double-qubit gates by manipulating fourfold degeneracy'. Together they form a unique fingerprint.

Cite this