7 papers
Efficient Quantum Circuit Construction of Controlled Time-Evolution for Arbitrary Pauli-Sum Hamiltonians
Shintaro Fujiwara, Naoki Yamamoto, Naoki Ishikawa
Controlled time-evolution circuits select forward or backward Hamiltonian time evolution according to the state of an ancilla qubit. They are fundamental building blocks in quantum…
Penalty-Free Two-Step Optimization of Higher-Order Ising Problems for Two-Dimensional Line-Controlled RIS
Tasuku Okamoto, Naoki Ishikawa, Daisuke Kitayama +5
Reconfigurable intelligent surfaces (RISs) are often assumed to allow continuous phase control over all elements, leading to hardware cost that scales with the number of elements.…
Scalable and Near-Optimal Discrete Phase Shift Optimization for Reconfigurable Intelligent Surfaces with Over 20,000 Elements
Yuto Hama, Daisuke Kitayama, Kensuke Inaba +4
This paper proposes a novel optimization framework for discrete phase shifts of a reconfigurable intelligent surface (RIS) using a coherent Ising machine (CIM). Unlike conventional…
Quantum-Accelerated Wireless Communications: Concepts, Connections, and Implications
Naoki Ishikawa, Giuseppe Thadeu Freitas de Abreu, Petar Popovski +1
Quantum computing is poised to redefine the algorithmic foundations of communication systems. While quantum superposition and entanglement enable quadratic or exponential speedups…
Grover Adaptive Search for the Higher-Order Formulation of Quadratic Assignment Problems
Taku Mikuriya, Shintaro Fujiwara, Kein Yukiyoshi +2
We demonstrate that the search space of the quadratic assignment problem (QAP), known as an NP-hard combinatorial optimization problem, can be reduced using Grover adaptive search…
Grover Adaptive Search with Spin Variables
Shintaro Fujiwara, Naoki Ishikawa
This paper presents a novel approach to Grover adaptive search (GAS) for a combinatorial optimization problem whose objective function involves spin variables. While the GAS algori…