We feel really honoured to give a talk before active researchers in this frontier field of physics, gauge theory and gravity. Although the member of our group are not familiar with the details of concepts and theoretical approachs in this field, we understand the importance of the Aharonov-Bohm effect in the electromagnetism, i.e. the first example of gauge fields. I) 2)-4) Since the theoretical work by Aharonov and Bohm in 1959, several experiments have been performed to prove this effect and these experiments have been fairly famous also among electron-microscopist.We thought the effect has the sound basis beyond doubt but we noticed also that a few people5)still insisted on its non-existance or doubted the validity of the experiments and that the controversy still continued. 6j' Therefore it seemed worth while to try an experiment in a newly designed form to confirm the effect again. This was our motivation.Before going into our experiment, let us explain briefly about those in the past.The schematic diagram in Fig.l shows the idea of the elaborate experiment by M~llenstedt group. 2} ' The lens and bi-prism are, of cource, electro-magnetic ones in fact. They fabricated a fine solenoid coil whose diameter was unbelievably small, 4.7 pm.Two electron waves from the same source travel around the solenoid and are overlapped coherently to cause interference fringes on the film below. Even if the waves never touch the magnetic flux inside the solenoid, the fringe must be shifted with the change in the phase difference between the waves owing to the Aharonov-Bohm effect when the coil current ~ changes. In order to confirm the fringe shift, they set a slit over the recoreding film and moved the film with changing the coil current i.The result is reproduced in Fig.2. The fringe shift is clearly recorded.'3j-4Lre~ " sl i art Other experiments a "m'l o this one in principle except that ferromagnetic needles were used instead of solenoids.All these experiments were very elaborate ones for the technology of those days but we must admit that they have one defect in common. That is, the lack of experimental verifications that there is no magnetic flux leakage into the electron paths.To improve this points, Kuper7)proposed in 1980 the idea of perfect confinement of magnetic fluxon by a hollow torus of super-conductive material, as shown in Fig.3.

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New peroxopolyacids based on tungsten and niobium (Nb‐HPA) were synthesized and investigated as negative inorganic resist materials for microlithography. Amorphous and microstructure‐free thin films, obtained from their water‐based solution using a conventional spin‐coating technique, exhibited sensitivity to deep UV ( D0.5=150 normalmJ/cm2 , Xe‐Hg lamp), E‐beam (10 μC/cm2, 30 kV) and x‐ray (120 mJ/cm2, Mo L). The O2‐RIE resistivity of Nb‐HPA film was found to be 50 times greater than that of polyimide resin (PIQ resin). Patterns as fine as 0.2 μm with an aspect ratio of 7.5 were successfully fabricated through the E‐beam bilayer process in which the bottom layer was PIQ (1.5 μm thickness) and the top, Nb‐HPA (0.1 μm).