(Invited) Integrating Classical Semiconductor Devices with Si/Sige Quantum Dots

As semiconductor based quantum devices scale up from single to multiple qubits there is an increasing need to integrate classical semiconductor based devices to manage and generate control signals.  We discuss progress on integrating field-effect transistors with planar quantum dot devices to achieve a high level of device throughput by creating on-chip multiplexers for our devices.  Using the on-chip multiplexers we can overcome the challenge of the limited number of electrical connections available in a typical dilution refrigerator while still working at the milli-Kelvin temperatures necessary for quantum operations.  Additionally, we report on recent work on gate designs for scaling up to multiple, coupled Si/SiGe qubits.  In particular we discuss the design, fabrication and initial characterization of quadruple quantum dot devices. 

This work was supported in part by the U.S. Army Research Office (W911NF-08-1-0482, W911NF-12-1-0607), the United States Department of Defense, and by the Laboratory Directed Research and Development program at Sandia National Laboratories.  Sandia National Laboratories is a multi-program laboratory managed and operated by Sandia Corporation, a wholly owned subsidiary of Lockheed Martin Corporation, for the U.S. Department of Energy's National Nuclear Security Administration under contract DE-AC04-94AL85000.  The views and conclusions contained in this document are those of the authors and should not be interpreted as representing the official policies, either expressly or implied, of the US Government. Development and maintenance of the growth facilities used for fabricating samples is supported by DOE (DE-FG02-503ER46028).