pith. machine review for the scientific record. sign in

Hamiltonian Simulation by Qubitization

6 Pith papers cite this work. Polarity classification is still indexing.

6 Pith papers citing it
abstract

We present the problem of approximating the time-evolution operator $e^{-i\hat{H}t}$ to error $\epsilon$, where the Hamiltonian $\hat{H}=(\langle G|\otimes\hat{\mathcal{I}})\hat{U}(|G\rangle\otimes\hat{\mathcal{I}})$ is the projection of a unitary oracle $\hat{U}$ onto the state $|G\rangle$ created by another unitary oracle. Our algorithm solves this with a query complexity $\mathcal{O}\big(t+\log({1/\epsilon})\big)$ to both oracles that is optimal with respect to all parameters in both the asymptotic and non-asymptotic regime, and also with low overhead, using at most two additional ancilla qubits. This approach to Hamiltonian simulation subsumes important prior art considering Hamiltonians which are $d$-sparse or a linear combination of unitaries, leading to significant improvements in space and gate complexity, such as a quadratic speed-up for precision simulations. It also motivates useful new instances, such as where $\hat{H}$ is a density matrix. A key technical result is `qubitization', which uses the controlled version of these oracles to embed any $\hat{H}$ in an invariant $\text{SU}(2)$ subspace. A large class of operator functions of $\hat{H}$ can then be computed with optimal query complexity, of which $e^{-i\hat{H}t}$ is a special case.

citation-role summary

background 2 method 1

citation-polarity summary

years

2026 6

representative citing papers

Gauss law codes and vacuum codes from lattice gauge theories

quant-ph · 2026-04-07 · unverdicted · novelty 8.0

Gauss law codes identify the full gauge-invariant sector as the code space while vacuum codes restrict to the matter vacuum, with the two shown to be unitarily equivalent for finite gauge groups.

Generalized Complexity Distances and Non-Invertible Symmetries

hep-th · 2026-04-15 · unverdicted · novelty 7.0

Non-invertible symmetries define quantum gates with generalized complexity distances, and simple objects in symmetry categories turn out to be computationally complex in concrete 4D and 2D QFT examples.

Unitaria: Quantum Linear Algebra via Block Encodings

quant-ph · 2026-05-11 · accept · novelty 4.0

Unitaria is a new open-source Python library that provides a high-level, composable interface for block encodings in quantum computing, enabling automatic circuit generation and classical simulation-based verification.

citing papers explorer

Showing 6 of 6 citing papers.