# A fast, low-leakage, high-fidelity two-qubit gate for a programmable superconducting quantum computer

@inproceedings{Rol2019AFL, title={A fast, low-leakage, high-fidelity two-qubit gate for a programmable superconducting quantum computer}, author={M. A. Rol and F. Battistel and F. Malinowski and C. C. Bultink and B. Tarasinski and R. Vollmer and N. Haider and N. Muthusubramanian and A. Bruno and B. Terhal and L. DiCarlo}, year={2019} }

A common approach to realize conditional-phase (CZ) gates in transmon qubits relies on flux control of the qubit frequency to make computational states interact with non-computational ones using a fast-adiabatic trajectory to minimize leakage. We develop a bipolar flux-pulsing method with two key advantages over the traditional unipolar variant. First, the action of the bipolar pulse is robust to long-timescale linear-dynamical distortions in the flux-control line, facilitating tuneup and… Expand

#### 11 Citations

Realization of efficient quantum gates with a superconducting qubit-qutrit circuit

- Computer Science, Medicine
- Scientific Reports
- 2019

A superconducting circuit for implementing a tunable system consisting of a qutrit coupled to two qubits and a conditional geometric gate which may be used for holonomic (non-adiabatic) quantum computing is proposed. Expand

Machine-learning based three-qubit gate for realization of a Toffoli gate with cQED-based transmon systems

- Computer Science, Physics
- ArXiv
- 2019

This work designs a controlled-controlled-phase gate with fidelity of >99.99% for nearest-neighbor coupled transmons in circuit quantum electrodynamics architectures and realizes a Toffoli gate which is widely used in quantum circuits, logic synthesis, quantum error correction, and quantum games. Expand

Spectral quantum tomography

- Physics
- 2019

We introduce spectral quantum tomography, a simple method to extract the eigenvalues of a noisy few-qubit gate, represented by a trace-preserving superoperator, in a SPAM-resistant fashion, using low… Expand

Protecting quantum entanglement from leakage and qubit errors via repetitive parity measurements

- Physics, Medicine
- Science Advances
- 2020

This work investigates how two-transmon entangled states evolve under repeated parity measurements and demonstrates the use of hidden Markov models to detect leakage using only the record of parity measurement outcomes required for QEC. Expand

Protecting quantum entanglement by repetitive measurement

- Computer Science
- 2020

The theory of quantum error correction (QEC) overcomes complications by encoding quantum information in entangled states of many qubits and performing parity measurements to identify errors in the system without destroying the encoded information. Expand

Designing Gates and Architectures for Superconducting Quantum Systems

- Physics
- 2020

Large-scale quantum computers can solve certain problems that are not tractable by currently available classical computational resources. The building blocks of quantum computers are qubits. Among… Expand

Alibaba Cloud Quantum Development Platform: Surface Code Simulations with Crosstalk

- Computer Science, Physics
- 2020

This note simulates a distance-3 logical qubit encoded in the 17-qubit surface code using experimental noise parameters for transmon qubits in a planar circuit QED architecture and shows that at the current-stage noise levels, crosstalk contributes significantly to the dephasing of the logical qubits. Expand

OpenQL : A Portable Quantum Programming Framework for Quantum Accelerators

- Computer Science, Physics
- ArXiv
- 2020

This paper proposes a quantum programming framework named OpenQL, which includes a high-level quantum programming language and its associated quantum compiler, and presents the programming interface, the different layers of the compiler and how it can provide portability over different qubit technologies. Expand

High-Contrast ZZ Interaction Using Superconducting Qubits with Opposite-Sign Anharmonicity.

- Medicine, Physics
- Physical review letters
- 2020

This work theoretically demonstrates that by coupling the two types of qubits, the high-contrast ZZ interaction can be realized, and introduces a superconducting architecture using qubits with opposite-sign anharmonicity, a transmon qubit, and a C-shunt flux qubit to address this issue. Expand

High-contrast ZZ interaction using multi-type superconducting qubits

- Physics
- 2020

For building a scalable quantum processor with superconducting qubits, the ZZ interaction is of great concert because of relevant for implementing two-qubit gates, and the close contact between gate… Expand