Comprehensive explanation of ZZ coupling in superconducting qubits
- URL: http://arxiv.org/abs/2408.15402v1
- Date: Tue, 27 Aug 2024 20:53:31 GMT
- Title: Comprehensive explanation of ZZ coupling in superconducting qubits
- Authors: Simon Pettersson Fors, Jorge Fernández-Pendás, Anton Frisk Kockum,
- Abstract summary: A major challenge for scaling up superconducting quantum computers is unwanted couplings between qubits.
We introduce analytical and numerical techniques, including a diagrammatic perturbation theory and a state-assignment algorithm.
We showcase these techniques for a system consisting of two fixed-frequency transmon qubits connected by a flux-tunable transmon coupler.
- Score: 0.0
- License: http://creativecommons.org/licenses/by/4.0/
- Abstract: A major challenge for scaling up superconducting quantum computers is unwanted couplings between qubits, which lead to always-on ZZ couplings that impact gate fidelities by shifting energy levels conditional on qubit states. To tackle this challenge, we introduce analytical and numerical techniques, including a diagrammatic perturbation theory and a state-assignment algorithm, as well as a refined intuitive picture for the workings of the ZZ coupling. Together, these tools enable a deeper understanding of the mechanisms behind the ZZ coupling and facilitate finding parameter regions of weak and strong ZZ coupling. We showcase these techniques for a system consisting of two fixed-frequency transmon qubits connected by a flux-tunable transmon coupler. There, we find three types of parameter regions with zero or near-zero ZZ coupling, all of which are accessible with current technology. We furthermore find regions of strong ZZ coupling nearby, which may be used to implement adiabatic controlled-phase gates. Our methods are applicable to many types of qubits and open up for the design of large-scale quantum computers with improved gate fidelities.
Related papers
- Modeling and Suppressing Unwanted Parasitic Interactions in Superconducting Circuits [0.8780132973107815]
Superconducting qubits are among the most promising candidates for building quantum computers.
This thesis addresses the parasitic interaction between coupled qubits in two- and three-qubit circuits.
arXiv Detail & Related papers (2024-07-11T09:07:45Z) - Lattice Hamiltonians and Stray Interactions Within Quantum Processors [0.6053347262128919]
This study highlights the significance of incorporating the lattice Hamiltonian into quantum circuit design.
By comparing the intensity of three-body versus two-body stray couplings, we identify non-trivial circuit parameter domains that help to enhance fidelity of two-qubit gates.
arXiv Detail & Related papers (2024-02-14T12:52:48Z) - Quantum Gate Optimization for Rydberg Architectures in the Weak-Coupling
Limit [55.05109484230879]
We demonstrate machine learning assisted design of a two-qubit gate in a Rydberg tweezer system.
We generate optimal pulse sequences that implement a CNOT gate with high fidelity.
We show that local control of single qubit operations is sufficient for performing quantum computation on a large array of atoms.
arXiv Detail & Related papers (2023-06-14T18:24:51Z) - Quantum process tomography of continuous-variable gates using coherent
states [49.299443295581064]
We demonstrate the use of coherent-state quantum process tomography (csQPT) for a bosonic-mode superconducting circuit.
We show results for this method by characterizing a logical quantum gate constructed using displacement and SNAP operations on an encoded qubit.
arXiv Detail & Related papers (2023-03-02T18:08:08Z) - Generation of perfectly entangled two and three qubits states by
classical random interaction [0.0]
This study examines the possibility of finding perfect entanglers for a Hamiltonian.
In this study, we use a superconducting circuit that stands out from other quantum-computing devices.
Our scheme could contribute to quantum teleportation, quantum communication, and some other areas of quantum information processing.
arXiv Detail & Related papers (2022-12-06T16:27:58Z) - Multi-squeezed state generation and universal bosonic control via a
driven quantum Rabi model [68.8204255655161]
Universal control over a bosonic degree of freedom is key in the quest for quantum-based technologies.
Here we consider a single ancillary two-level system, interacting with the bosonic mode of interest via a driven quantum Rabi model.
We show that it is sufficient to induce the deterministic realization of a large class of Gaussian and non-Gaussian gates, which in turn provide universal bosonic control.
arXiv Detail & Related papers (2022-09-16T14:18:53Z) - Optimal quantum control via genetic algorithms for quantum state
engineering in driven-resonator mediated networks [68.8204255655161]
We employ a machine learning-enabled approach to quantum state engineering based on evolutionary algorithms.
We consider a network of qubits -- encoded in the states of artificial atoms with no direct coupling -- interacting via a common single-mode driven microwave resonator.
We observe high quantum fidelities and resilience to noise, despite the algorithm being trained in the ideal noise-free setting.
arXiv Detail & Related papers (2022-06-29T14:34:00Z) - Scalable High-Performance Fluxonium Quantum Processor [0.0]
We propose a superconducting quantum information processor based on compact high-coherence fluxoniums with suppressed crosstalk.
We numerically investigate the cross resonance controlled-NOT and the differential AC-Stark controlled-Z operations, revealing low gate error for qubit-qubit detuning bandwidth of up to 1 GHz.
arXiv Detail & Related papers (2022-01-23T21:49:04Z) - Realization of arbitrary doubly-controlled quantum phase gates [62.997667081978825]
We introduce a high-fidelity gate set inspired by a proposal for near-term quantum advantage in optimization problems.
By orchestrating coherent, multi-level control over three transmon qutrits, we synthesize a family of deterministic, continuous-angle quantum phase gates acting in the natural three-qubit computational basis.
arXiv Detail & Related papers (2021-08-03T17:49:09Z) - Universal non-adiabatic control of small-gap superconducting qubits [47.187609203210705]
We introduce a superconducting composite qubit formed from two capacitively coupled transmon qubits.
We control this low-frequency CQB using solely baseband pulses, non-adiabatic transitions, and coherent Landau-Zener interference.
This work demonstrates that universal non-adiabatic control of low-frequency qubits is feasible using solely baseband pulses.
arXiv Detail & Related papers (2020-03-29T22:48:34Z) - High-contrast ZZ interaction using superconducting qubits with opposite-sign anharmonicity [15.172882153788267]
We introduce a superconducting architecture using qubits with opposite-sign anharmonicity, a transmon qubit and a C-shunt flux qubit.
We can control the interaction with a high on/off ratio to implement two-qubit CZ gates, or suppress it during two-qubit gate operation using XY interaction.
arXiv Detail & Related papers (2020-02-18T13:53:06Z)
This list is automatically generated from the titles and abstracts of the papers in this site.
This site does not guarantee the quality of this site (including all information) and is not responsible for any consequences.