Slow phase relaxation can prevent meltdown in quantum computers

Abstract:
We show that phase memory can be much longer than energy relaxation in systems with exponentially large dimensions of Hilbert space [1]; this finding is documented by fifty years of nuclear experiments, though the information is somewhat hidden. For quantum computers Hilbert spaces of dimention of 2^100 (2 in power 100) or larger will be typical and therefore this effect may contribute significantly to reduce the problems of scaling of quantum computers to a useful number of qubits. We propose a theoretical interpretation of the anomalously long phase memory based on the study of highly excited microscopic many-body systems [2-5].

[1] J. Flores, S.Yu. Kun, T. Seligman, submitted.
[2] S.Yu. Kun, B.A. Robson, A.V. Vagov, Phys. Rev. Lett., vol. 83, 504 (1999).
[3] S.Yu. Kun, Phys. Rev. Lett., vol. 84, 423 (2000), and refs. therein.
[4] Wang Qi, S.Yu. Kun et al., Int. J. Mod. Phys. E, vol. 12, 377 (2003), and refs. therein.
[5] S.Yu. Kun, L. Benet, L.T. Chadderton, W. Greiner, F. Haas, Phys. Rev. C, vol. 67, 011604(R) (2003), and refs. therein.