We report controllable coupling between coherent excitations in a silicon transistor, which is useful for double-qubit gate operation. Coupling interactions may be directed by adjusting the gate voltage in a semiconductor device or by an additional flux in a superconducting device. Here, we demonstrate an alternative approach to coupling by exploiting the nonlinear behavior of the silicon transistor. Microwave spectroscopy on a DC-biased transistor has previously been found to indicate the presence of coherent oscillating electrons. We couple two such resonances by using triple-frequency spectroscopy, where the third frequency corresponds to the frequency difference between the two on-resonance frequencies. © 2011 American Institute of Physics.
- single electron transistors
- microwave spectroscopy