Electric field effect control of a superconducting YBa2Cu3O7 inductor

We discuss the design, fabrication, and testing of a thin-film superconducting voltage-controlled inductor which is made from a YBa2Cu3O7 (YBCO) superconducting field effect transistor. Applying voltage to an Au gate layer alters the areal carrier density, and hence the kinetic inductance, of an underlying 100-nm-thick YBCO channel layer. The channel is connected in series with an input coil to form a closed superconducting loop. We use a dc superconducting quantum interference device at 4.2 K to measure changes in loop inductance and find a fractional change in the kinetic inductance of about +2.6×10−4/V of applied gate voltage, close to the expected value.