Photonics technologies: Mobile whole-head SQUID system of SNS junctions in a superconducting magnetic shield

Abstract

Constructed was a mobile whole-head SQUID system of SNS (Superconductor/Normal metal/Superconductor) junctions in a superconducting magnetic shield. The whole-head SQUID system in the superconducting magnetic shield is 100 times more sensitive than that in a magnetically shielded room of Permalloy. Nanometer-scale SNS junctions have the comparable size to the wavelength of the beat of de Bloglie waves of an electron and a hole to be a mesoscopic system. The established theory of mesoscopic SNS junctions is as elegant as Planck theory of blackbody radiation. SQUID systems enable invasive studies about recognition in human brains. They have response time of millisecond to be a good tool for experimental confirmation of neural models of human brain obtaining information about memory, attention and learning in long latencies. They are expected to make some contribution to studies about autism, ADHD and LD. The SQUID system has successfully detected magnetic fields from human brains both in crowded Nano tech 2003 held at Makuhari Messe convention center and Nanotech 2004 at Tokyo Big Sight Exhibition Center. The success could be the first step to mobile clinic for mental care.