Macroscopic Quantum Coherence and Quantum Computing

457 Pages·2001·26.897 MB·English

by  A. J. Leggett (auth.), Dmitri V. Averin, Berardo Ruggiero, Paolo Silvestrini (eds.)

Macroscopic Quantum
Coherence and
Quantum Computing
Macroscopic Quantum
Coherence and
Quantum Computing
Edited by
Dmitri V. Averin
State University of New York at Stony Brook
Stony Brook, New York
Berardo Ruggiero
Instituto di Cibemetica
Naples, Italy
and
Paolo Silvestrini
Instituto di Cibemetica
Naples, Italy
Produeed under the auspiees of the
Istituto Italiano Studi Filosofiei
Springer Science+Business Media, LLC
Proceedings of the International Workshop on Macroscopic Quantum Coherence and Computing
MQC2 Istituto Italiano per gli Studi Filosofiei, held June 14-17, 2000, in Naples, Italy
ISBN 978-1-4613-5459-8 ISBN 978-1-4615-1245-5 (eBook)
DOI 10.1007/978-1-4615-1245-5
© 2001 Springer Science+Business Media New York
Origina1ly published by Kluwer Academic /Plenum Publishers, New York in 2001
Softcover reprint ofthe hardcover Ist edition 2001
http://www.wkap.nll
ill 9 8 7 6 5 4 3 2 1
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PREFACE
This volume is an outgrowth of the Second International Workshop on
Macroscopic Quantum Coherence and Computing held in Napoli, Italy, in June
2000. This workshop gathered a number of experts from the major Universities
and Research Institutions of several countries. The choice of the location, which
recognizes the role and the traditions of Naples in this field, guaranteed the
participants a stimulating atmosphere.
The aim of the workshop has been to report on the recent theoretical
and experimental results on the macroscopic quantum coherence of macroscopic
systems. Particular attention was devoted to Josephson devices. The correlation
with other atomic and molecular systems, exhibiting a macroscopic quantum
behaviour, was also discussed. The seminars provided both historical overview
and recent theoretical ground on the topic, as well as information on new
experimental results relative to the quantum computing area.
The first workshop on this topic, held in Napoli in 1998, has been
ennobled by important reports on observations of Macroscopic Quantum
Coherence in mesoscopic systems. The current workshop proposed, among
many stimulating results, the first observations of Macroscopic Quantum
Coherence between macroscopically distinct fluxoid states in rf SQUIDs, 20
years after the Leggett's proposal to experimentally test the quantum behavior
of macroscopic systems. Reports on observations of quantum behaviour in
molecular and magnetic systems, small Josephson devices, quantum dots have
also been particularly stimulating in view of the realization of several possible
q-bits.
The present volume, far from being exhaustive, represents an
interesting update of the subject and hopefully, a further stimulation. We hope
that this will be a useful tool in promoting new experiments.
In conclusion, we wish to thank the Istituto Italiano per gli Studi
Filosofici, the Istituto di Cibernetica del Consiglio Nazionale delle Ricerche, the
State University of New York at Stony Brook, the Istituto Nazionale di Fisica
Nucleare, the Istituto Nazionale di Fisica della Materia, the Dipartimento
Scienze Fisiche dell' Universita di Napoli "Federico II", and the Gruppo
Nazionale di Fisica della Materia del CNR for their support. This initiative is
v
vi Preface
within the scope of the MQC2 Association, Naples, Italy for international
interchanges on "Macroscopic Quantum Coherence and Computing."
We are indebted to Valentina Corato for scientific assistance, and to E.
Degrazia and A. M. Mazzarella for their valuable assistance in all the tasks
connected to the organization of the Workshop.
We are also grateful to E. Esposito, C. Granata, L. Keller, A. Monaco,
and S. Piscitelli for hints and help during the organization of the Workshop.
Thanks are due to L. De Felice and V. Sindoni for the organization of
the social event.
Paolo Silvestrini
CONTENTS
Macroscopic Quantum Coherence and Decoherence in SQUIDs .................. 1
A. J. Leggett
Macroscopic Quantum Coherence in an Rf-SQUID ....................................... 7
Jonathan R. Friedman, Vijay Patel, W. Chen, S. K. Tolpygo,
and J. E. Lukens
Quantum-State Interference in a Cooper-Pair Box ...................................... 17
Y. Nakamura, Yu. A. Pashkin, and J. S. Tsai
Macroscopic Quantum Superposition in a Three-Josephson-Junction
Loop .................................................................................................... 25
Caspar H. van der Wal, A. C. J. ter Haar, F. K. Wilhelm,
R. N. Schouten, C. J. P. M. Harmans, T. P. Orlando,
Seth Lloyd, and J. E. Mooij
Bose-Einstein Condensation with Attractive Interaction: Fate of a
False Vacuum ..................................................................................... 35
M. Ueda and H. Saito
Macroscopic Quantum Phenomena in Atomic Bose-Einstein
Condensates ........................................................................................ 41
Fernando Sols and Sigmund Kohler
Phase-Coherent Electronic Transport in a Multi-Wall Carbon
Nanotube .................................................................................................. 51
Nam Kim, Jinhee Kim, Jong Wan Park, Kyung-Hwa Yoo,
Jeong-O Lee, Kicheon Kang, Hyun-Woo Lee,
and Ju-Jin Kim
Macroscopic Quantum Phenomena in Underdamped Josephson
Junctions .................................................................................................. 61
V. Corato, E. Esposito, C. Granata, B. Ruggiero, M. Russo,
and P. Silvestrini
vii
viii Contents
Superconducting Devices to Test Macroscopic Quantum
Coherence on the Flux States of an Rf SQUID ................................. 73
C. Cosmelli, P. Cappelletti, P. Carelli, M. G. Castellano,
F. Chiarello, G. Diambrini Palazzi, R. Leoni,
N. Milanese, and G. Torrioli
Biepitaxial YBa2Cu307_x Grain Boundary Josephson Junctions: 0-
and n-Rings for Fundamental Studies and Potential
Circuit Implementation ......................................................................... 83
Francesco Tafuri, Franco Carillo, Filomena Lombardi,
Fabio Miletto Granozio, Fabrizio Ricci,
Umberto Scotti di Uccio, Antonio Barone, Gianluca Testa,
Ettore Samelli, and John R. Kirtley
The Superconducting Single Electron Transistor: In Situ
Variation of the Dissipation ................................................................ 101
J. B. Kycia, J. Chen, R. Therrien, (:. Kurdak, K. L. Campman,
A. C. Gossard, and John Clarke
Superconducting Electrometer for Measuring the Single Cooper
Pair Box ................................................................................................. 111
A. Cottet, A. Steinbach, P. Joyez, D. Vion, H. Pothier, D. Esteve,
and M. E. Huber
Adiabatic Transport of Cooper Pairs in Arrays of Small Josephson
Junctions ................................................................................................ 127
J. P. Pekola, J. J. Toppari, N. Kim, M. T. Savolainen, L. Taskinen,
and K. Hansen
Entangled States in a Josephson Charge QuBit Coupled to a
Superconducting Resonator ............................................................... 137
O. Buisson and F. W. J. Hekking
Cooper Pair Tunneling in Circuits with Substantial Dissipation:
The Three-Junction R-Pump for Single Cooper Pairs .................. 147
A. B. Zorin, S. A. Bogoslovsky, S. V. Lotkhov, and J. Niemeyer
Nonlocality in Superconducting Microstructures .......................................... 155
K. Yu. Arutyunov, J. P. Pekola, A. B. Pavolotski, and D. A. Presnov
Contents ix
Characterisation of Cooper Pair Boxes for Quantum Bits .......................... 165
M. T. Savolainen, 1. 1. Toppari, L. Talskinen, N. Kim, K. Hansen,
and 1. P. Pekola
Noise Measurements of a Superconducting Single Electron
Transistor (SSET) at T=O.3 K ............................................................ 173
B. Buonomo, P. Carelli, M. G. Castellano, F. Chiarello,
C. Cosmelli, R. Leoni, and G. Torrioli
Quantum Coherence and Decoherence in Magnetic Nanostructures ........ 183
Eugene M. Chudnovsky
MQT of Magnetic Particles ............................................................................... 195
Wolfgang Wernsdorfer
Abrupt Transition between Thermally-Assisted and Pure
Quantum Tunneling in MN 12 ............................................................. 207
K. M. Mertes, Yicheng Zhong, M. P. Sarachik, Y. Paltiel,
H. Shtrikman, E. Zeldov, Evan Rumberger,
and D. N. Hendrickson
Quantum Effects in the Dynamics of the Magnetization in Single
Molecule Magnets ................................................................................ 215
D. Gatteschi, R. Sessoli, and W. Wernsdorfer
Quantum Coherence and Very Low Temperature Magnetic
Experiments in Mesoscopic Magnets ................................................ 225
1. Tejada, 1. M. Hernandez, E. del Barco, N. Biskup, 1. Brooks.
and M. D. Zyzler
Quantum Gates and Networks with Cavity QED Systems .......................... 235
D. Vitali, V. Giovanetti, and P. Tombesi
Dual Josephson Phenomena: Interaction of Vortices with Non-
Classical Microwaves ........................................................................... 245
A. Vourdas, A. Konstadopoulou, and 1. M. Hollingworth
Quantum Computation: Theory, Practice, and Future Prospects ............. 253
Isaac L. Chuang
x Contents
Reading-out a Quantum State: An Analysis of the Quantum
Measurement Process .......................................................................... 261
Yu. Makhlin, G. Schon, and A. Shnirman
Adiabatic Inversion in the SQUID, Macroscopic Coherence, and
Decoherence .......................................................................................... 271
P. Silvestrini and L. Stodolsky
Quantum Computing with Separable States? ................................................ 285
Rudiger Schack
Spintronics and Quantum Computing with Quantum Dots ........................ 293
Patrik Recher, Daniel Loss. and Jeremy Levy
Double Quantum Dot Coupled to Two Superconductors:
Transport and Spin Entanglement.. .................................................. 307
Mahn-Soo Choi, Christoph Bruder. and Daniel Loss
Transport through Artificial Kondo Impurities ............................................ 317
S. De Franceschi, S. Sasaki, J. M. Elzerman, W. G. van der Wiel,
S. Tarucha, and L. P. Kouwenhoven
Compensation ofthe Spin ofa Quantum Dot at Coulomb Blockade ......... 325
Domenico Giuliano. Benoit Jouault, and Arturo Tagliacozzo
Multi-Particle Entanglement in Quantum Computers ................................. 341
Klaus M01mer and Anders S0rensen
Stabilization of Quantum Information: A Unified Dynamical-
Algebraic Approach ............................................................................. 351
Paolo Zanardi
l/F Noise during Manipulation of Josephson Charge Qubits ..................... 359
E. Paladino, L. Faoro, G. Falci, and Rosario Fazio
Non-Markovian Dynamics in Continuous-Wave Atom Lasers ................... 367
H. P. Breuer, D. Faller, B. Kappler, and F. Petruccione
Time-Correlated Macroscopic Quantum Tunneling of Solitons in
Density Waves and Long Josephson Junctions ............................... 381
John H. Miller, Jr.
Contents xi
The Non-Perturbative Quantum Behaviour of a SQUID Ring in a
Strong Electromagnetic Field ............................................................. 389
M. J. Everit P. Stiffell, 1. F. Ralph, T. D. Clark. A.Vourdas,
H. Prance, and R. 1. Prance
Noise Properties of the SET Transistor in the Co-Tunneling
Regime .................................................................................................... 399
D. V. Averin
Charge Fluctuations and Dephasing in Coulomb Coupled
Conductors ............................................................................................ 409
Markus Buttiker
The Measurement of Photon Number States Using Cavity QED ............... 419
Simon Brattke, Benjamin Varcoe, and Herbert Walther
Abrupt Magnetoresistance Jumps in Ni-Wire Systems and
Coulomb Blockade Under Elastic Environment in Single
Junction/Carbon Nanotube System ................................................. .427
1. Haruyama, I. Takesue, S. Kato, K. Takazawa, and Y Sato
Spontaneous Generation of Flux in a Josephson Junction Loop ................ 443
Raz Carmi. Emil Polturak, and Gad Koren
Soliton Quantum Bit ........................................................................................... 449
Noriyuki Hatakenaka and Hideaki Takayanagi
Index ...................................................................................................................... 459