We previously reported on Intel’s development of the Horse Ridge and Horse Ridge II cryogenic control chips that would allow generation of the necessary microwave pulses to control spin qubits at a temperature of 3 degrees kelvin right near the qubits themselves. This eliminates the requirement to route coaxial cables from external room temperature control electronics down to the qubits through the refrigerator, which becomes extremely difficult as the number of qubits increases. In a paper published this week in Nature, Intel and QuTech performance data of the Horse Ridge chip in a system. The first test was to evaluate the electrical performance of the chip itself which showed fidelity results of 99.99% matching what could be achieved with room temperature electronics. The second test was to use the chip to provide single qubit gate control and it showed results of 99.7% fidelity with the limiting factor being the qubits themselves rather than the control signals from Horse Ridge chip. The third test was to implement a simple Deutsch-Jozsa algorithm using the chip and its capability to control two qubits with the same cable using a frequency multiplexing capability. These results show one more step for achieving a large scalable quantum computer that by showing a potential solution to the cabling problem that would occur with a system containing a large number of qubits. Additional information about this development can be found in a news release from Intel available here, another news release from QuTech available here, and the technical paper published in Nature here.
May 14, 2021