de Haas–van Alphen effect and Fermi surface of ${\mathrm{YBa}}_2$${\mathrm{Cu}}_3$${\mathrm{O}}_{6.97}$

The component of the magnetic susceptibility periodic in 1/B, the de Haas–van Alphen effect, has been investigated using a 100-T flux compression system. It is concluded from these measurements that ${\mathrm{YBa}}_2$ ${\mathrm{Cu}}_3$ ${\mathrm{O}}_{6.97}$ exhibits a Fermi surface with at least three separate extremal frequencies for the c axis parallel to the applied field. Orbital masses, renormalization λ’s, and scattering rates are estimated from an amplitude analysis.