Lattice Hamiltonians and stray interactions within quantum processors
Xuexin Xu, Manabputra, Chloé Vignes, Mohammad H. Ansari, John M. Martinis · Physical Review Applied · 2024
This study's modeling of superconducting quantum processors reveals that, contrary to popular belief, three-body ZZZ stray couplings can surpass parasitic ZZ interactions, posing a serious threat to gate fidelity and crosstalk. Even more striking, strongly decoupled qubits---long thought to be ideal---can be more problematic than loosely coupled ones, even when idle. These findings overturn traditional design principles and force us to rethink next-generation architectures for quantum processors.