Abstract
This presentation provides an overview of my team’s recent work, spanning the design of a quantum instruction set and its implications for system performance, quantum error correction, and chip architecture.
Since Shor’s algorithm demonstrates quantum computing’s potential for exponential speedups in solving critical problems like integer factorization, the field has drawn sustained, intense interest from both academia and industry. From fundamental physics experiments in the 1990s laboratories—where only a handful of qubits could be manipulated—–to today’s ability to precisely control hundreds of qubits for preliminary computing trials, humanity stands analogous to our ancestors when they first mastered fire: we are now learning to harness the revolutionary power of qubit manipulation. In this talk, I will focus on key advancements in the design principles and engineering implementation of quantum computing instruction set architectures, outline the major challenges currently faced, and discuss directions for future development.
The systematic exploration of non-conventional quantum instruction sets only commenced a few years back. demonstrates that the underexplored √'iSWAP' significant advantages in both expressivity and fidelity—challenging the longheld assumption of a trade-off between these two properties. Partially inspired by parallel efforts to explore alternative twoqubit instructions, introduced a unified control scheme capable of implementing arbitrary two-qubit gates efficiently. By tuning physical parameters such as pulse envelope amplitudes and frequency detuning, this approach enables, for the first time, direct and flexible realization of any two-qubit unitary operation. The so-called AshN scheme was subsequently validated through a series of experiments on superconducting quantum processors], confirming its feasibility.
This line of research, while striving to achieve a better balance between expressivity and accuracy, may nonetheless introduce unforeseen drawbacks—particularly concerning compatibility with established techniques. For instance, the widely used virtual-Z technique can fail when applied to two-qubit gates that do not preserve phase (i.e., those that are not phase carriers). To address this limitation, proposes a compilation scheme for arbitrary single-qubit gates on superconducting processors. The method leverages tunable phase shifts of microwave pulses to realize a continuous gate set, is compatible with any two-qubit gate, and requires calibration of only the X(π) and X( π 2 ) pulses.
By integrating all the aforementioned advances, it is unsurprising that quantum algorithms can now be implemented far more effectively than with conventional synthesis into CNOT and single-qubit gates. Notably—and somewhat surprisingly—early work in this direction, such as, not only demonstrates significant performance gains but also shows promise in mitigating the challenges posed by limited qubit connectivity, a key limitation of superconducting platforms compared to trappedions or neutral atoms.
However, in the regime of quantum error correction—where stabilizer operations and Clifford gates are of primary interest—it remains unclear how much benefit the aforementioned nonconventional instruction sets will offer. By leveraging both CNOT and iSWAP instructions, mitigates the impact of ancilla qubit defects during surface code stabilizer measurements, thereby enhancing the robustness and reliability of quantum computation. Moreover, similar techniques can be extended to quantum low-density parity-check (qLDPC) codes, offering the advantage of halving the number of required long-range interactions.
Much like early fire-builders learned to shape flame into tools, we are now shaping quantum interactions into reliable, programmable computation—turning raw physical potential into engineered reality. And just as the spark was essential to kindling fire, the quantum instruction set serves as the ignition point in this transformation—deserving far greater attention and dedicated research.