Digital quantum computation with superconducting qubits

Quantum simulation, as a practical application of noisy quantum computing, has aided the study of exotic quantum matters and the implementation of algorithms that outperform classical approaches. Superconducting qubits, one of the most promising candidates for realizing universal quantum computing, possess state-of-the-art features like easy integration of qubits, long coherence time, and high-fidelity single- and two-qubit gates. These characteristics have enabled applications of digital quantum simulation in the fields of physics, chemistry, and computer science. In this review, we first present the basic concepts of superconducting qubits, quantum gates, and digital quantum simulations. We also explore recent progress in digital quantum simulations using superconducting qubits, especially in relation to quantum chemistry, quantum matters, combinatorial optimization, and quantum machine learning. Finally, we address the current challenges of digital quantum simulation with superconducting qubits, and provide a perspective on the future of the field.Quantum simulation, as a practical application of noisy quantum computing, has aided the study of exotic quantum matters and the implementation of algorithms that outperform classical approaches. Superconducting qubits, one of the most promising candidates for realizing universal quantum computing, possess state-of-the-art features like easy integration of qubits, long coherence time, and high-fidelity single- and two-qubit gates. These characteristics have enabled applications of digital quantum simulation in the fields of physics, chemistry, and computer science. In this review, we first present the basic concepts of superconducting qubits, quantum gates, and digital quantum simulations. We also explore recent progress in digital quantum simulations using superconducting qubits, especially in relation to quantum chemistry, quantum matters, combinatorial optimization, and quantum machine learning. Finally, we address the current challenges of digital quantum simulation with superconducting qubits, and provide a perspective on the future of the field.

Journal of Zhejiang University. Science AOct 1, 20241 citation

Superconducting circuit architecture for digital-analog quantum computing

Jing Yu, J. C. Retamal, Mikel Sanz +2 more

Abstract We propose a superconducting circuit architecture suitable for digital-analog quantum computing (DAQC) based on an enhanced NISQ family of nearest-neighbor interactions. DAQC makes a smart use of digital steps (single qubit rotations) and analog blocks (parametrized multiqubit operations) to outperform digital quantum computing algorithms. Our design comprises a chain of superconducting charge qubits coupled by superconducting quantum interference devices (SQUIDs). Using magnetic flux control, we can activate/deactivate exchange interactions, double excitation/de-excitations, and others. As a paradigmatic example, we present an efficient simulation of an $\ell \times h$ ℓ × h fermion lattice (with $2<\ell \leq h$ 2 < ℓ ≤ h ), using only $2(2\ell +1)^{2}+24$ 2 ( 2 ℓ + 1 ) 2 + 24 analog blocks. The proposed architecture design is feasible in current experimental setups for quantum computing with superconducting circuits, opening the door to useful quantum advantage with fewer resources.Abstract We propose a superconducting circuit architecture suitable for digital-analog quantum computing (DAQC) based on an enhanced NISQ family of nearest-neighbor interactions. DAQC makes a smart use of digital steps (single qubit rotations) and analog blocks (parametrized multiqubit operations) to outperform digital quantum computing algorithms. Our design comprises a chain of superconducting charge qubits coupled by superconducting quantum interference devices (SQUIDs). Using magnetic flux control, we can activate/deactivate exchange interactions, double excitation/de-excitations, and others. As a paradigmatic example, we present an efficient simulation of an $\ell \times h$ ℓ × h fermion lattice (with $2<\ell \leq h$ 2 < ℓ ≤ h ), using only $2(2\ell +1)^{2}+24$ 2 ( 2 ℓ + 1 ) 2 + 24 analog blocks. The proposed architecture design is feasible in current experimental setups for quantum computing with superconducting circuits, opening the door to useful quantum advantage with fewer resources.

arXiv:2103.15696EPJ Quantum TechnologyApr 6, 202218 citations

Fast Microwave-free State Preparation and Measurement of Superconducting Qubits

R. Abraham, F. Amet, P. Anderson +212 more

Fast, high-fidelity, scalable state preparation and measurement is critical to the realization of a quantum computing system. The state-of-the-art methods for preparation and readout of superconducting qubits require finely tuned microwave signals and ~100 ns of measurement time, which are major obstacles to the scalability and performance of superconducting quantum computers. Here, we have demonstrated novel, microwave-free methods for both preparation and readout of superconducting qubits with >99% fidelity in only 10 ns for either operation while maintaining qubit coherence. This technology is compatible with scalable superconducting digital control systems, and using quantum flux parametrons for amplification, we demonstrated full quantum-to-digital conversion in only 15 ns, which is an order of magnitude faster than state-of-the-art microwave-based techniques.Fast, high-fidelity, scalable state preparation and measurement is critical to the realization of a quantum computing system. The state-of-the-art methods for preparation and readout of superconducting qubits require finely tuned microwave signals and ~100 ns of measurement time, which are major obstacles to the scalability and performance of superconducting quantum computers. Here, we have demonstrated novel, microwave-free methods for both preparation and readout of superconducting qubits with >99% fidelity in only 10 ns for either operation while maintaining qubit coherence. This technology is compatible with scalable superconducting digital control systems, and using quantum flux parametrons for amplification, we demonstrated full quantum-to-digital conversion in only 15 ns, which is an order of magnitude faster than state-of-the-art microwave-based techniques.

quant-pharXiv:2609.01334Sep 2, 20260 citations

Quantum Computing Utilizing the Superconducting Quantum Qubit

Daisuke Saida

The Journal of The Institute of Image Information and Television EngineersJan 1, 20220 citations

\ell \times h

ℓ × h fermion lattice (with

2<\ell \leq h

2 < ℓ ≤ h ), using only

2(2\ell +1)^{2}+24

2 ( 2 ℓ + 1 ) 2 + 24 analog blocks. The proposed architecture design is feasible in current experimental setups for quantum computing with superconducting circuits, opening the door to useful quantum advantage with fewer resources.