Autori: Giancarlo Franzese[1,4], Vittorio Cataudella[2,4], Rosario Fazio[3,4]

[1]Dip. di Fisica ``E.Amaldi'', Università Roma III
[2]Dip. di Scienze Fisiche, Universittà di Napoli
[3]Dip. di Metodologie Chimiche e Fisiche per l'Ingegneria, Universittà di Catania
[4]Istituto Nazionale per la Fisica della Materia (INFM)

We introduce [1] a fully frustrated XY model with nearest neighbor (nn) and next nearest neighbor (nnn) couplings which could play a relevant role in low temperature regime of usual Josephson junction arrays and can be realized in specially designed setups [2].
We study the phase diagram for 0<= x <=1 (x is the ratio between nn and nnn couplings). When x <= 0.7 an Ising-like and a Kosterlitz-Thouless-Berezinskii-like transitions are present (both decrease with increasing x). For x >= 0.8 only the latter transition occurs. Above x=0.8 the transition temperature rapidly increases toward the x->oo limit and the reentrant phase could be experimentally detected.

Referenze

1. V.Cataudella, G.Franzese, R.Fazio, in preparation.
2. H.Courtois and P.Martinoli (private communication).

• Ritorno alla pagina principale.