Phase engineering techniques in superconducting quantum electronics

Due to the pulse driven nature of the Rapid Single Flux Quantum electronics nearly every basic cell requires the capability of temporary data storing. Implementing phase shifting elements in this essential device leads to several advantages concerning the device characteristics. There are different concepts enabling phase shifting elements. We give a comparative overview about these approaches. The effect of this novel element on a basic cell is analyzed exampling a toggle-flip-flop. Based on the effective noise temperature determined from the experimental results of a standard flip-flop, the bit error rate for several toggle-flip-flop realizations containing different phase shifting elements was calculated. A significantly improved area of function could be shown by simulated error rates lower than 10-12 with a DC bias margin better than ±63.5%.

[1]  M. Weides,et al.  High quality ferromagnetic 0 and π Josephson tunnel junctions , 2006, cond-mat/0604097.

[2]  Q.P. Herr,et al.  Error rate of RSFQ circuits: theory , 1997, IEEE Transactions on Applied Superconductivity.

[3]  V. Oboznov,et al.  Thickness dependence of the Josephson ground States of superconductor-ferromagnet-superconductor junctions. , 2006, Physical review letters.

[4]  E. K. Track,et al.  Superconductor ICs: the 100-GHz second generation , 2000 .

[5]  M. Siegel,et al.  Multiple 0-π transitions in superconductor/insulator/ferromagnet/superconductor Josephson tunnel junctions , 2006 .

[6]  Julian Satchell.  Limitations on HTS single flux quantum logic , 1999, IEEE Transactions on Applied Superconductivity.

[7]  V. K. Kaplunenko,et al.  Rapid single-flux quantum logic using π-shifters , 2003 .

[8]  Characteristics of strong ferromagnetic Josephson junctions with epitaxial barriers , 2005, cond-mat/0502537.

[9]  J. E. Mooij,et al.  Simple phase bias for superconducting circuits , 2001, cond-mat/0112433.

[10]  F.-I. Buchholz,et al.  Superconductive passive phase shifter for integrated RSFQ digital circuits , 2007 .

[11]  J. Aarts,et al.  Coupling of Two Superconductors through a Ferromagnet , 2001 .

[12]  O. Mielke,et al.  RSFQ Circuitry Using Intrinsic $\pi$-Phase Shifts , 2007, IEEE Transactions on Applied Superconductivity.

[13]  K. Likharev,et al.  Rapid single flux quantum T-flip flop operating up to 770 GHz , 1999, IEEE Transactions on Applied Superconductivity.

[14]  O. Mielke,et al.  Flip-Flopping Fractional Flux Quanta , 2006, Science.

[15]  Konstantin K. Likharev,et al.  Experimental study of the RSFQ logic elements , 1989 .

[16]  F.-I. Buchholz,et al.  Passive Phase Shifter for Superconducting Josephson Circuits , 2007, IEEE Transactions on Applied Superconductivity.

[17]  V. Semenov,et al.  RSFQ logic/memory family: a new Josephson-junction technology for sub-terahertz-clock-frequency digital systems , 1991, IEEE Transactions on Applied Superconductivity.

[18]  N. Yoshikawa,et al.  Bit-Error-Rate Measurements of RSFQ Shift Register Memories , 2007, IEEE Transactions on Applied Superconductivity.

[19]  J Aarts,et al.  Coupling of two superconductors through a ferromagnet: evidence for a pi junction. , 2001, Physical review letters.