On the possible key experiments to show the singlet-to-triplet conversion of the Cooper pairs by the use of a SFCO-method

Abstract

The problem of electron pairing above Meissner expel arose when high-Tc superconductive (HTS) materials were discovered. And scientists are admitting know that there is need to consider 2 processes for HTS: electron pairing and long-range phase coherence among Cooper pairs (pair condensation) – separately and independently each other. Otherwise, it is admitted, that in HTS electrons become paired above Meissner expel (above T0, starting from Tc) & start forming SC-condensate only at T0, while in low-Tc SC materials (LTS) the pairing and pair condensation start simultaneously (T0 = Tc). But, since discovery of HTS new data appeared and importance of some earlier data was recognized, indicating analogy among the HTS and LTS in connection with these 2 processes. Here we show that there are no differences among these materials regarding the said processes: electron pairing and pair condensation are separate & independent even in LTS. Difference is in a temperature scale. For LTS these processes run in a narrow range (∼30mK), while in HTS the scale is longer (for YBaCuO, more than 3K). This is the reason why separation of Tc from T0 in LTS is so hard so far. The problem is still open also due to lack of methods for "nonperturbative" study of the beginnings of SC transition in clean (tiny) objects with small signal. Analysis of data permits to conclude that becomes urgent sensitive study of the Fulde-Ferrell-Larkin-Ovchinnikov superconductivity in heavy-fermion materials that have layered electronic structure. And, the SFCO method may stand key tool for sensitive study of the pair formation in FFLO state. Such a study may show singlet-to-triplet conversion of Cooper pairs. It may also allow separating the ideal conducting (R = 0) & ideal diamagnetic (B = 0) states, which are important for true interpretation of a real nature of superconductivity.