ar X iv : 0 70 9 . 18 94 v 2 [ co nd - m at . m es - h al l ] 1 6 O ct 2 00 7 Direct mechanical mixing in a nanoelectromechanical diode

We observe direct mechanical mixing in nanoelectromechanical transistors fabricated in semiconductor materials operating in the radio frequency band of 10 ∼ 1000 MHz. The device is made of a mechanically flexible pillar with a length of 240 nm and a diameter of 50 nm placed between two electrodes in an impedance matched coplanar wave guide. We find a nonlinear I-V characteristic, which enables radio frequency mixing of two electromagnetic signals via the nanomechanical transistor. Potential applications for this mixer are ultrasensitive displacement detection or signal processing in communication electronic circuits requiring high-throughput insulation.