| Low
dimensional systems are characterized by strong quantum fluctuations. In
the presence of disorder these fluctuations change their nature leading
to new and fascinating new phenomena. Systems like La2 CuO4
are very good antiferromagnets, however, when doped with charge carriers
(such as in the case of La2-x Srx CuO4
- LSCO) they lose magnetic order very rapidly (in LSCO it occurs at x=0.02)
given rise to a complex SPIN
GLASS phase that is poorly understood. On the other hand, when La2
CuO4 is diluted with non-magnetic atoms as in the case of La2 Cu1-z (Zn,Mg)z
O4 order is only lost at z=0.41 with the suppression of quantum effects
in a very non-trivial way. |
