Coherence time Archives - IEEE Transactions on Quantum Engineering

SU(4) Gate Design via Unitary Process Tomography: Its Application to Cross-Resonance-Based Superconducting Quantum Devices

July 3, 2025Michihiko Sugawara; Takahiko SatohPhysical ImplementationsCalibration, Coherence time, Logic gates, Qubit, Resonance, Schedules, Superconducting microwave devices, Systematics, Tensors, Tomography

Abstract: In this article, we present a novel approach for implementing pulse-efficient SU(4) gates on cross resonance (CR)-based superconducting quantum devices. Our method introduces a parameterized unitary derived from the CR-Hamiltonian propagator, which accounts for ZZ-interactions. Leveraging the Weyl chamber’s geometric structure, we successfully realize a continuous two-qubit basis gate, RZZ(θ), as an echo-free pulse […]

Runtime–Coherence Tradeoffs for Hybrid Satisfiability Solvers

April 22, 2025Vahideh Eshaghian; Sören Wilkening; Johan Åberg; David GrossQuantum ComputingCoherence time, Hardware, Optimization, Partitioning algorithms, Polynomials, Quantum algorithm, Qubit, Runtime, Search problems, Visualization

Abstract: Many search-based quantum algorithms that achieve a theoretical speedup are not practically relevant since they require extraordinarily long coherence times, or lack the parallelizability of their classical counterparts. This raises the question of how to divide computational tasks into a collection of parallelizable subproblems, each of which can be solved by a quantum computer […]

Resource Placement for Rate and Fidelity Maximization in Quantum Networks

July 23, 2024Shahrooz Pouryousef, Hassan Shapourian, Alireza Shabani, Ramana Kompella, Don TowsleyQuantum Networking & CommunicationsCoherence time, Optimization, Planning, Quantum entanglement, Quantum repeaters, Qubit, Repeaters

Existing classical optical network infrastructure cannot be immediately used for quantum network applications due to photon loss. The first step toward enabling quantum networks is the integration of quantum repeaters into optical networks. However, the expenses and intrinsic noise inherent in quantum hardware underscore the need for an efficient deployment strategy that optimizes the placement […]

Resource Placement for Rate and Fidelity Maximization in Quantum Networks

July 23, 2024Shahrooz Pouryousef, Hassan Shapourian, Alireza Shabani, Ramana Kompella, Don TowsleyQuantum InternetCoherence time, Optimization, Planning, Quantum entanglement, Quantum repeaters, Qubit, Repeaters