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Magnetoencephalography using high temperature rf SQUIDs

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We have developed high-critical-temperature radio-frequency Super conducting QUantum Interference Devices (SQUIDs) with step-edge grain-boundary Josephson junctions and large flux focusers. These planar devices were fabricated from epitaxial YBa2Cu3O7 films and operated in the magnetometer and first-order gradiometer configurations while immersed in liquid nitrogen. At the temperature of 77K, we have attained a magnetic field resolution for the magnetometer better than 200 fT/Hz1/2 down to less than 1 Hz, i.e., over the low signal frequency range important for medical diagnostics. The results to date show a high promise for biomagnetic diagnostics. For the first time, we recorded the evoked responses from human brains using a high-temperature magnetometer and a first-order electronic gradiometer channel simultaneously. These results were obtained in a magnetically shielded room. An improvement in the magnetic field resolution by another order of magnitude is possible and probable.

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  1. DiIorio, M.S. Reproducible low-noise SQUIDs at 77K. Bull. Am. Phys. Soc., 1992, 36: 261.

  2. Friedl, G., Vildic, M., Roas, B., Uhl, D., Bömmel, F., Römheld, M., Hillenbrand, B., Stritzker, B. and Daalmans, G. Low 1/f noise YBCO SQUID at 77K. Appl. Phys. Lett., June 15, 1992.

  3. Koch, R.H, Umbach, C.P., Clark, G.J., Chaudhari, P. and Laibowitz, R.B. Quantum interference devices made from superconducting oxide thin films. Appl. Phys. Lett., 1987, 51: 200–202.

  4. Lee, L.P., Char, K., Colclough, M.S. and Zaharchuk, G. Monolithic 77K dc SQUID magnetometer. Appl. Phys. Lett., 1991, 59: 3051–3053.

  5. Miklich, A.H., Kingston, J.J., Wellstood, F.C., Clarke, J., Colclough, M.S., Char, K. and Zaharchuk, G. Thin film YBCO magnetometer. Nature, 1991, 352: 482–483.

  6. Zhang, Y., Mück, M., Herrmann, K., Schubert, J., Zander, W., Braginski, A.I. and Heiden, C. Low-noise YBCO rf SQUID magnetometer. Appl. Phys. Lett., 1992, 60: 645–647.

  7. Zhang, Y., Mück, M., Bode, M., Herrmann, K., Schubert, J., Zander, W., Braginski, A.I. and Heiden, C. Microwave rf SQUID integrated into a planar YBCO resonator. Appl. Phys. Lett., 1992c, 60: 2303–2306.

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Correspondence to Y. Zhang.

Additional information

We are grateful to Prof. Dr. med. M. Hoke, Director of the Institute for Experimental Audiology for his support and the encouragement offered to us. We also thank Dr. J. Schubert and W. Zander, KFA-ISI, who fabricated the YBCO films by pulsed laser deposition. Work at KFA was supported, in part, by the German Minister of Research and Technology (BMFT), the Consortium on "First Applications of HTS in Microelectronics".

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Zhang, Y., Tavrin, Y., Mück, M. et al. Magnetoencephalography using high temperature rf SQUIDs. Brain Topogr 5, 379–382 (1993). https://doi.org/10.1007/BF01128694

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Key words

  • High-temperature superconductor
  • Thin-film
  • Biomagnetism
  • Diagnostics
  • Magnetoencephalography
  • Auditory evoked fields