Lucci Massimiliano, Cassi Davide, Merlo Vittorio, Russo Roberto, Salina Gaetano, Cirillo Matteo
Dipartimento di Fisica and MINAS Lab, Università di Roma "Tor Vergata", 00133 Roma, Italy.
Istituto Nazionale di Fisica Nucleare, Sezione di Roma "Tor Vergata", 00133 Roma, Italy.
Entropy (Basel). 2021 Jun 25;23(7):811. doi: 10.3390/e23070811.
Evidence is reported that topological effects in graph-shaped arrays of superconducting islands can condition superconducting energy gap and transition temperature. The carriers giving rise to the new phase are couples of electrons (Cooper pairs) which, in the superconducting state, behave as predicted for bosons in our structures. The presented results have been obtained both on star and double comb-shaped arrays and the coupling between the islands is provided by Josephson junctions whose potential can be tuned by external magnetic field or temperature. Our peculiar technique for probing distribution on the islands is such that the hopping of bosons between the different islands occurs because their thermal energy is of the same order of the Josephson coupling energy between the islands. Both for star and double comb graph topologies the results are in qualitative and quantitative agreement with theoretical predictions.
有证据表明，超导岛的图形阵列中的拓扑效应会影响超导能隙和转变温度。产生新相的载流子是电子对（库珀对），在超导状态下，它们的行为符合我们结构中玻色子的预测。我们在星形和双梳形阵列上都得到了这些结果，岛之间的耦合由约瑟夫森结提供，其电势可通过外部磁场或温度进行调节。我们用于探测岛上分布的特殊技术使得玻色子在不同岛之间的跳跃得以发生，因为它们的热能与岛之间的约瑟夫森耦合能处于同一量级。对于星形和双梳形图形拓扑结构，结果在定性和定量上都与理论预测相符。
