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 (HF) metals (like UPt3) as the weak link (N) can be useful thermosensors. This property is due to the large thermopower of HF metals which is of the order (10−5–10−6) V/K at temperatures T<10 K. Furthermore, the longitudinal sound applied to such a weak link can generate voltage oscillations. This effect is due to the large electronic Grüneisen parameter Ωhf in HF metals, where Ωhf∼102 like in UPt3. Similar effects are expected with other Kondo systems.