An experimental microarchitecture for a superconducting quantum processor

Abstract

Quantum computers promise to solve certain problems that are intractable for classical computers, such as factoring large numbers and simulating quantum systems. To date, research in quantum computer engineering has focused primarily at opposite ends of the required system stack: devising high-level programming languages and compilers to describe and optimize quantum algorithms, and building reliable low-level quantum hardware. Relatively little attention has been given to using the compiler output to fully control the operations on experimental quantum processors. Bridging this gap, we propose and build a prototype of a exible control microarchitecture supporting quantum-classical mixed code for a superconducting quantum processor. The microarchitecture is based on three core elements: (i) a codeword-based event control scheme, (ii) queue-based precise event timing control, and (iii) a exible multilevel instruction decoding mechanism for control. We design a set of quantum microinstructions that allows exible control of quantum operations with precise timing. We demonstrate the microarchitecture and microinstruction set by performing a standard gate-characterization experiment on a transmon qubit.

eQASM: An Executable Quantum Instruction Set Architecture

“…We instantiate eQASM into a 32-bit instruction set targeting a seven-qubit superconducting quantum processor and implement it using a control microarchitecture derived from MA as proposed in [1]. We validated eQASM by performing several experiments over a two-qubit superconducting quantum processor using the implemented microarchitecture.…”

“…A hybrid compilation infrastructure compiles the host program into classical code using a conventional compiler such as GCC, which is later executed by the classical host CPU. e quantum compiler, such as OpenQL [1], compiles the quantum kernels in two steps. First, quantum kernels are compiled into QASM, or a similar format mathematically equivalent to the circuit model.…”

“…But existing quantum assembly languages either incorporate too high-level constructs to be directly implemented by a microarchitecture (including QASM-HL [11], il [12], f-QASM [13], etc. ), or are too restricted to provide a comprehensive abstraction of the quantum hardware which can support the required ow control (including OpenQASM [14], MIS [1], etc.). is fact signi cantly limits the range of quantum so ware which can be executed by the hardware.…”

Formal constraint-based compilation for noisy intermediate-scale quantum systems

“…Recently, Fu et al [29], developed QuMA, a microarchitecture for QC systems based on superconducting qubits. QuMA takes compiler generated quantum instructions as input and uses micro-instructions to achieve precise timing control of the physical qubits.…”

Towards Efficient Superconducting Quantum Processor Architecture Design

“…In particular, the superconducting quantum circuit [5] has become one of the most promising technique candidates for building QC systems [6][7][8] due to the ever-increasing qubit coherence time, individual qubit addressability, fabrication technology scalability, etc. Towards efficient superconducting quantum circuit based QC system, significant research has recently been conducted, ranging from compiler optimization [9,10] to periphery control hardware support [11,12] and device innovation [13,14].…”