High Temperature Superconductivity Arising in a Metal Sheet Full of Holes

Abstract

By drilling periodic thru-holes in a suspended film, the phonon system can be modified. Being motivated by the BCS theory, the technique, so-called phonon engineering, was applied to a niobium sheet. The newly emergent high-Tc superconductivity, however, cannot be accounted for by the BCS theory. Rather, its exposed configuration, namely a square-lattice oxygen network, is reminiscent of the copper--oxygen plane in cuprate high-Tc superconductors. It turns out that its magnetic result is consistent with the principle of giant atom, which was developed by another heroes of superconductivity, Fritz London and John Slater, in the 1930s, several decades earlier than the propagation of BCS theory. The superconducting transition feature is discussed on the basis of a comprehensive theory of the giant atom---the theory of hole superconductivity.

Ultimate speed of the supercurrent and its pairing mechanism

“…( 3) and ( 4) are valid only in 2D cases. This indicates that the RTSC in this study is indeed a '2D superconductor', which must reflect a key role of 2D phonon engineering 2 that nullifies 3D components of electron momentum as explained before 1 . Another indication of Eq.…”

“…In the second warming process (orange), the resistance dropped to zero at 39 K, and the zero-resistance state was retained with the temperature warmed up to 300 K. Thus it has been revealed again that the warming process is indeed beneficial to superconductivity, and in this way the room-temperature superconductor (RTSC) has arrived. Besides the phenomenological explanation given by the G-L theory, the dynamics of the superconducting transition as well was discussed in the previous paper 1 based on the Hirsch's theory of hole superconductivity [4][5][6] . The theory teaches us the absolute benefit of lattice expansion that lowers the orbital kinetic energy of an atom at each lattice point.…”

“…Then, by what means does the second hole overcome such a strong repulsive situation and occupy the same orbit with its partner? It could be chemical hole doping, physical hole currents repeatedly applied as was done for this study 1 or oxygen transformation associated with the Jahn-Teller theorem 20 . By whatever means, once an extra h + hops into an h + -orbit, the [h + × h + ]-orbit gets unstable, expands and goes superconducting.…”

“…In the previous study 1 , resistive and magnetic properties of a periodically perforated metal sheet designed by phonon engineering 2 were investigated. During temperature cycles, the metallic two-dimensional (2D) square lattice exhibited both resistance drop to zero and magnetization drop, i.e., the Meissner effect.…”