2013/01/31 by B. D. Clader, B. C. Jacobs, C. R. Sprouse · 1 citation
Physics and Astronomy · #quant-ph
paper · pdf · doi:10.1103/physrevlett.110.250504
published as Phys. Rev. Lett. 110, 250504 (2013) · 5 pages; Substantial revisions, including addition of preconditioner
arxiv created 2013/05/07 · arxiv updated 2013/06/25
We describe a quantum algorithm that generalizes the quantum linear system algorithm [Harrow et al., Phys. Rev. Lett. 103, 150502 (2009)] to arbitrary problem specifications. We develop a state preparation routine that can initialize generic states, show how simple ancilla measurements can be used to calculate many quantities of interest, and integrate a quantum-compatible preconditioner that greatly expands the number of problems that can achieve exponential speedup over classical linear systems solvers. To demonstrate the algorithm's applicability, we show how it can be used to compute the electromagnetic scattering cross section of an arbitrary target exponentially faster than the best classical algorithm.