Siddiqi qubit. By integrating an effective band-block filter on chip, we overcome this trade-off and realize a Kerr-cat qubit in a scalable 2D superconducting circuit with high coherence. Our group, the Quantum Nanoelectronics Laboratory, investigates the quantum coherence of various condensed matter systems ranging from microscopic nanomagnets such as single molecule magnets to complex macroscopic electrical circuits. Qutrits, or quantum three-level systems, can provide advantages over qubits in certain quantum information applications, and high-fidelity single-qutrit gates have been demonstrated. Here by adiabatically transforming fixed-frequency superconducting circuits into modifiable Floquet qubits, we demonstrate an XXZ Heisenberg interaction with fully adjustable anisotropy. Author(s): Siddiqi, Irfan | Abstract: Advances in materials science and engineering have played a central role in the development of classical computers and will undoubtedly be critical in propelling the maturation of quantum information technologies. Siddiqi is known for groundbreaking contributions to the field of superconducting quantum circuits, including dispersive single-shot readout of superconducting quantum bits, quantum feedback, observation of single quantum trajectories, and near-quantum limited microwave frequency amplification. Real-time quantum feedback based on weak measurement of the quantum state is used to stabilize the oscillation phase of a driven quantum bit. This circuit has a special bias point where the Larmor frequency is, to first order, insensitive to fluctuations in the bias parameters---the charge of the box island and the phase of the large junction. AQT conducts pioneering research in superconducting quantum computers, exploring novel qubit designs, processor architectures, and control systems, and collaboratively developing a comprehensive platform to accelerate innovation and discovery in quantum information science and technology. The efficiency of running quantum algorithms can be improved by expanding the hardware operations that a quantum computer can perform. Here, using fixed-frequency superconducting qubits, we demonstrate a high-fidelity iToffoli gate based on two-qubit interactions, the so-called cross-resonance effect. Inspired by the GKP encoding scheme, we implement a superconducting qubit whose eigenstates form protected grid states – long envisioned but not previously realized – by integrating an effective Cooper-quartet junction with a quantum phase-slip element embedded in a high-impedance circuit. A neutral network shows the ability to infer complex quantum behavior of a superconducting qubit without any prior knowledge about the rules of quantum physics. The Quantum Nanoelectronics Laboratory investigates the quantum coherence of various condensed matter systems ranging from microscopic nanomagnets such as single molecule magnets to complex macroscopic electrical circuits. This filter provides 30 dB of isolation at the qubit frequency with negligible attenuation at the frequencies required for stabilization and readout. Goss et al 8 QUBIT CHIP UNIFORMITY REQUIREMENTS Two-qubit gate (cross resonance gate) places strict requirements on detuning of neighboring qubits relative to anharmonicity ( ). Many current qubit designs have fixed energy levels and consequently limited types of controllable interactions. Irfan Siddiqi is a professor in the Department of Physics. Several three-qubit gates have been implemented for superconducting qubits, but their use in gate synthesis has been limited due to their low fidelity. Aug 29, 2025 · Introducing the symmetrically threaded SQUID Kerr-cat qubit: a superconducting qubit design with longer lifetimes, paving the way for scalable, fault-tolerant quantum computing. . A high-fidelity three-qubit iToffoli gate has now been They studied a qubit consisting of a superconducting device embedded in a microwave cavity with fluctuations likely to cause decoherence. The ``quantronium'' is a superconducting qubit consisting of a split Cooper pair box in which a large tunnel junction is inserted. Apr 25, 2024 · By integrating an effective band-block filter on-chip, we overcome this trade-off and realize a Kerr-cat qubit in a scalable 2D superconducting circuit with high coherence. In approaches to quantum computation based on superconducting circuits, as one goes from bulk materials to functional devices, amorphous films 8 QUBIT CHIP UNIFORMITY REQUIREMENTS Two-qubit gate (cross resonance gate) places strict requirements on detuning of neighboring qubits relative to anharmonicity ( ). At this optimal working point, the state of the qubit can be By integrating an effective band-block filter on-chip, we overcome this trade-off and realize a Kerr-cat qubit in a scalable 2D superconducting circuit with high coherence. xgphvk, 5zusf0, bgmo, brps, krjcir, yt9i, jniy7, 1vbv, cup1, ohbr,