We propose a quantum processor for the scalable quantum computation based on microwave photons in 1D superconducting resonators. Different from the previous processors which are composed of some resonators coupled to a superconducting qubit, our processor is composed of some resonators
ri and a common resonator R acting as a quantum bus, which makes it have the capability of integrating more resonators simply by coupling them to the bus
R in different positions. R is coupled to only one transmon qutrit, and the coupling strengths between
ri and R can be fully tuned. To show the processor can be used to achieve universal quantum computation effectively, we present a scheme to complete the high-fidelity quantum state transfer between two microwave-photon resonators and another one for the high-fidelity controlled-phase gate on them.
As superconducting quantum computing continues to advance at an unprecedented pace, there is a compelling demand for the innovation of specialized electronic instruments that act as crucial conduits between quantum processors and host computers. Here, we introduce a Microwave Measurement and Control System (M2CS) dedicated for large-scale superconducting quantum processors. M2CS features a compact modular design that balances overall performance, scalability, and flexibility. Electronic tests of M2CS show key metrics comparable to commercial instruments. Benchmark tests on transmon superconducting qubits further show qubit coherence and gate fidelities comparable to state-of-the-art results, confirming M2CS's capability to meet the stringent requirements of quantum experiments run on intermediate-scale quantum processors. The system's compact and scalable design offers significant room for further enhancements that could accommodate the measurement and control requirements of over 1000 qubits, and can also be adopted to other quantum computing platforms such as trapped ions and silicon quantum dots. The M2CS architecture may also be applied to wider range of scenarios, such as microwave kinetic inductance detectors, as well as phased array radar systems.
Superconducting quantum processors are among the most advanced quantum computing technologies. Systems based on these devices have enabled post-classical computation [1] and proof-of-concept execution of quantum-error-correction protocols [2]. While other qubit technologies employ naturally-occurring quantum mechanical degrees of freedom to encode information, those used by superconducting qubits are defined at the circuit level. Today’s state-of-the-art superconducting quantum processors use transmon qubits, but these are just one of a rich set of superconducting qubits; in considering the system-level optimization of a large-scale quantum computer, alternative qubit topologies may prove advantageous. Here, we consider cryo-CMOS control of a fluxonium qubit, one of the most promising of emerging superconducting qubits.