We propose a novel deterministic method for preparing arbitrary quantum states. When our protocol is compiled into CNOT and arbitrary single-qubit gates, it prepares an-dimensional state in depthand(a metric that accounts for the fact that oftentimes some ancilla qubits need not be active for the entire circuit), which are both optimal. When compiled into thegate set, we show that it requires asymptotically fewer quantum resources than previous methods. Specifically, it prepares an arbitrary state up to errorwith optimal depth ofand spacetime allocation, improving overand, respectively. We illustrate how the reduced spacetime allocation of our protocol enables rapid preparation of many disjoint states with only constant-factor ancilla overhead –ancilla qubits are reused efficiently to prepare a product state of-dimensional states in depthrather than, achieving effectively constant depth per state. We highlight several applications where this ability would be useful, including quantum machine learning, Hamiltonian simulation, and solving linear systems of equations. We provide quantum circuit descriptions of our protocol, detailed pseudocode, and gate-level implementation examples using Braket.
- Award ID(s):
- 1730449
- NSF-PAR ID:
- 10213496
- Date Published:
- Journal Name:
- Proceedings of the 50th International Symposium on Multiple-Valued Logic
- Page Range / eLocation ID:
- 303 to 308
- Format(s):
- Medium: X
- Sponsoring Org:
- National Science Foundation
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