250 citations · 705 across the 12 of their papers we have counts for
12 papers
Spacetime-Efficient Low-Depth Quantum State Preparation with Applications
Kaiwen Gui, Alexander M. Dalzell, Alessandro Achille +2
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 -dimensi…
Sparse random Hamiltonians are quantumly easy
Chi-Fang, Chen, Alexander M. Dalzell +3
A candidate application for quantum computers is to simulate the low-temperature properties of quantum systems. For this task, there is a well-studied quantum algorithm that perfor…
Mind the gap: Achieving a super-Grover quantum speedup by jumping to the end
Alexander M. Dalzell, Nicola Pancotti, Earl T. Campbell +1
We present a quantum algorithm that has rigorous runtime guarantees for several families of binary optimization problems, including Quadratic Unconstrained Binary Optimization (QUB…
End-to-end resource analysis for quantum interior point methods and portfolio optimization
Alexander M. Dalzell, B. David Clader, Grant Salton +8
We study quantum interior point methods (QIPMs) for second-order cone programming (SOCP), guided by the example use case of portfolio optimization (PO). We provide a complete quant…
Is there evidence for exponential quantum advantage in quantum chemistry?
Seunghoon Lee, Joonho Lee, Huanchen Zhai +15
The idea to use quantum mechanical devices to simulate other quantum systems is commonly ascribed to Feynman. Since the original suggestion, concrete proposals have appeared for si…
Quantum Resources Required to Block-Encode a Matrix of Classical Data
B. David Clader, Alexander M. Dalzell, Nikitas Stamatopoulos +3
We provide modular circuit-level implementations and resource estimates for several methods of block-encoding a dense matrix of classical data to precision ; the min…
Random quantum circuits transform local noise into global white noise
Alexander M. Dalzell, Nicholas Hunter-Jones, Fernando G. S. L. Brandão
We study the distribution over measurement outcomes of noisy random quantum circuits in the low-fidelity regime. We show that, for local noise that is sufficiently weak and unital,…
Random quantum circuits anti-concentrate in log depth
Alexander M. Dalzell, Nicholas Hunter-Jones, Fernando G. S. L. Brandão
We consider quantum circuits consisting of randomly chosen two-local gates and study the number of gates needed for the distribution over measurement outcomes for typical circuit i…
Efficient classical simulation of random shallow 2D quantum circuits
John Napp, Rolando L. La Placa, Alexander M. Dalzell +2
Random quantum circuits are commonly viewed as hard to simulate classically. In some regimes this has been formally conjectured, and there had been no evidence against the more gen…
Locally accurate MPS approximations for ground states of one-dimensional gapped local Hamiltonians
Alexander M. Dalzell, Fernando G. S. L. Brandao
A key feature of ground states of gapped local 1D Hamiltonians is their relatively low entanglement --- they are well approximated by matrix product states (MPS) with bond dimensio…
How many qubits are needed for quantum computational supremacy?
Alexander M. Dalzell, Aram W. Harrow, Dax Enshan Koh +1
Quantum computational supremacy arguments, which describe a way for a quantum computer to perform a task that cannot also be done by a classical computer, typically require some so…
Fixed-Point Adiabatic Quantum Search
Alexander M. Dalzell, Theodore J. Yoder, Isaac L. Chuang
Fixed-point quantum search algorithms succeed at finding one of target items among total items even when the run time of the algorithm is longer than necessary. While the f…