Advances in dynamic circuits at IBM

In a dynamic circuit, the outcome of qubit measurements must classically control quantum gates within the coherence time of the qubits. IBM has been in the vanguard of exploring and developing dynamic circuits, offering this capability to the public starting in 2022. On noisy hardware, a reliable and accurate dynamic circuit execution requires tight timing constraints and a tailor-made error suppression and mitigation. Importantly, dynamic circuits enhance the instruction set of the quantum hardware. They enable a more efficient implementation of quantum algorithms, exemplified by quantum phase estimation [1] and the quantum Fourier transform [2], and help distribute entanglement [3]. Furthermore, dynamic circuits are key to many protocols that rely on classical communication. Recently, dynamic circuits were used to operate two 127 superconducting qubit processors as a single quantum backend with 254 qubits using circuit cutting based on local operations and classical communication [4]. In this talk we will discuss IBM's recent advances in dynamic circuits touching on their execution and the functionality that they enable. We will review the lessons learned from early experiments and how we plan to revise the compilation and execution of dynamic circuits which is crucial to leverage their full potential.

[1] Corcoles et al., PRL 127, 100501 (2021)

[2] Baumer et al., arXiv:2403.09514 (2024)

[3] Baumer et al., PRX Quantum 5, 030339 (2024)

[4] Vazquez et al., Nature (2024)