Possible thermosensor on S-N-S weak link with N as heavy fermion metal

It is shown that S-N-S weak links with strongly correlated heavy-fermion (H F) metals (like UPt3) as the weak link (N) can be useful thermosensors. Thi s property is due to the large thermopower of HF metals which is of the ord er (10(-5)-10(-6)) V/K at temperatures T < 10 K. Furthermore, the longitudi nal sound applied to such a,weak link can generate voltage oscillations. Th is effect is due to the large electronic Gruneisen parameter Omega (ht) in HF metals, where Omega (hf) similar to 10(2) like in UPt3. Similar effects are expected with other Kondo systems. (C) 2001 Elsevier Science Ltd. All r ights reserved.