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On the complexity of implementing Trotter steps

Quantum dynamics can be simulated on a quantum computer by exponentiating elementary terms from the Hamiltonian in a sequential manner. However, such an implementation of Trotter steps has gate complexity depending on the total Hamiltonian term …

Provably accurate simulation of gauge theories and bosonic systems

Quantum many-body systems involving bosonic modes or gauge fields have infinite-dimensional local Hilbert spaces which must be truncated to perform simulations of real-time dynamics on classical or quantum computers. To analyze errors resulting from …

Fast-Forwardable Quantum Evolution and Where to Find Them

This is a Perspective on "Fast-forwarding quantum evolution" by Shouzhen Gu, Rolando D. Somma, and Burak Şahinoğlu, published in Quantum 5, 577 (2021).

Nearly tight Trotterization of interacting electrons

We consider simulating quantum systems on digital quantum computers. We show that the performance of quantum simulation can be improved by simultaneously exploiting commutativity of the target Hamiltonian, sparsity of interactions, and prior …

Faster Digital Quantum Simulation by Symmetry Protection

Simulating the dynamics of quantum systems is an important application of quantum computers and has seen a variety of implementations on current hardware. We show that by introducing quantum gates implementing unitary transformations generated by the …

A Theory of Trotter Error

The Lie-Trotter formula, together with its higher-order generalizations, provides a simple approach to decomposing the exponential of a sum of operators. Despite significant effort, the error scaling of such product formulas remains poorly …

Time-dependent Hamiltonian simulation with $L^1$-norm scaling

The difficulty of simulating quantum dynamics depends on the norm of the Hamiltonian. When the Hamiltonian varies with time, the simulation complexity should only depend on this quantity instantaneously. We develop quantum simulation algorithms that …

Approximate Quantum Fourier Transform with $O(n\log(n))$ T gates

The ability to implement the Quantum Fourier Transform (QFT) efficiently on a quantum computer facilitates the advantages offered by a variety of fundamental quantum algorithms, such as those for integer factoring, computing discrete logarithm over …

Faster quantum simulation by randomization

Product formulas can be used to simulate Hamiltonian dynamics on a quantum computer by approximating the exponential of a sum of operators by a product of exponentials of the individual summands. This approach is both straightforward and surprisingly …

Framework for Hamiltonian simulation and beyond: standard-form encoding, qubitization, and quantum signal processing

A unified framework for quantum simulation developed by Guang Hao Low and Isaac L. Chuang that leads to a simulation algorithm with not only optimal query complexity but also low ancilla overhead.