Marc A. Kastner
We have discovered that applying microwave light to the transistor can restore the Kondo effect for a quantum dot with a voltage applied between the leads. Figure A shows the conductance as a function of the microwave voltage (horizontal scale) applied to a quantum dot transistor. The bright red peak for zero microwaves corresponds to the weak bond, and increasing the voltage between the leads (vertical scale) destroys it. However, at increasing microwave voltages two new peaks appear. Figure B shows that the voltage difference between the central peak and one of the new ones is hf/e, where f is the microwave frequency. This means that microwave photons restore the Kondo bond when the photon energy hf equals the electrical energy eV.