6 papers · 1 filter
Approximate QCAs in one dimension using approximate algebras
Daniel Ranard, Michael Walter, Freek Witteveen
Quantum cellular automata (QCAs) are automorphisms of tensor product algebras that preserve locality, with local quantum circuits as a simple example. We study approximate QCAs, wh…
Lower bounding the MaxCut of high girth 3-regular graphs using the QAOA
Edward Farhi, Sam Gutmann, Daniel Ranard +1
We study MaxCut on 3-regular graphs of minimum girth for various 's. We obtain new lower bounds on the maximum cut achievable in such graphs by analyzing the Quantum Approxi…
The threshold for quantum-classical correspondence is
Felipe Hernández, Daniel Ranard, C. Jess Riedel
In chaotic quantum systems, an initially localized quantum state can deviate strongly from the corresponding classical phase-space distribution after the Ehrenfest time $t_{\mathrm…
Ehrenfest's theorem beyond the Ehrenfest time
Felipe Hernández, Daniel Ranard, C. Jess Riedel
In closed quantum systems, wavepackets can spread exponentially in time due to chaos, forming long-range superpositions in just seconds for ordinary macroscopic systems. A weakly c…
Learning State Preparation Circuits for Quantum Phases of Matter
Hyun-Soo Kim, Isaac H. Kim, Daniel Ranard
Many-body ground state preparation is an important subroutine used in the simulation of physical systems. In this paper, we introduce a flexible and efficient framework for obtaini…
Strategies for running the QAOA at hundreds of qubits
Brandon Augustino, Madelyn Cain, Edward Farhi +5
We explore strategies aimed at reducing the amount of computation, both quantum and classical, required to run the Quantum Approximate Optimization Algorithm (QAOA). First, followi…