Gallery Static electric field suppresses superconductivity!

Current-voltage (I −V) characteristics of a Ti supercurrent FET measured at 5 mK for several values of the applied gate voltage Vg (the hatched area is a guide to the eye emphasizing the monotonic suppression of the critical current Ic down to zero by increasing |Vg|. When the supercurrent vanishes, the I(V) characteristics coincide with that in the normal state, independently of the value of the applied gate voltage. The curves are horizontally offset for clarity.

A static electric field can be used to manipulate the superconducting state of metallic superconducting thin films, according to new experiments by researchers in Italy. The effect, which was first put forward by the London brothers, Fritz and Heinz, in their original formulation of superconductivity back in 1935, might be exploited in novel-concept devices such as supercurrent and Josephson field-effect transistors, as well as classical and possibly even quantum bits.
“It seems that we are realizing a novel phase of the superconducting state driven by electric fields,” says Francesco Giazotto of the Consiglio Nazionale delle Ricerche (CNR) and the Scuola Normale Superiore in Pisa, who led this research effort. “At the moment, we are unclear as to the type of phase transition we are inducing but our finding definitely represents something very intriguing from the fundamental physics point of view.”

More details on: