Fluxonium: Single Cooper-Pair Circuit Free of Charge Offsets

By V. Manucharyan, Jens Koch, L. Glazman, Michel H. Devoret. Science, 2009

749 citations recorded by the source corpus.

Quiet, Please One approach for building quantum computers is based on superconductors with appropriately designed components to control the pairs of charges flowing through the circuits. However, at the single-electron level, required quantum noise—generated by quantum fluctuations and throwing offset charges into the device—presents a real problem in manipulating the delicate quantum states of the qubits. Manucharyan et al. (p. 113) present a clever piece of quantum circuit engineering that can suppress the effect of the quantum noise and allow the quantum circuit to operate without disturbance. Circuit engineering was used to mitigate the effects of quantum noise in superconducting quantum circuits. The promise of single Cooper-pair quantum circuits based on tunnel junctions for metrology and quantum information applications is severely limited by the influence of offset charges: random, slowly drifting microscopic charges inherent in many solid-state systems. By shunting a small junction with the Josephson kinetic inductance of a series array of large-capacitance tunnel junctions, thereby ensuring that all superconducting islands are connected to the circuit by at least one large junction, we have realized a new superconducting artificial atom that is totally insensitive to offset charges. Yet its energy levels manifest the anharmonic structure associated with single Cooper-pair effects, a useful component for solid-state quantum computation.

Subfields: Artificial Intelligence, Atomic and Molecular Physics, and Optics

View Paper: https://www.semanticscholar.org/paper/99952656082b996c4dac1781a4a4181c5aa4290d

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Citations in the corpus

Introduction to quantum electromagnetic circuits (2016, background): “The fluxonium [49] artificial atom is a loop circuit made up of a small Josephson junction (with Josephson energy EJ and Coulomb energy EC ∼ EJ) in parallel with a large linear inductor, meaning that its inductive energy EL satisfies EL ≪ EJ .”
Quantum information processing and quantum optics with circuit quantum electrodynamics (2020, background): “Other contemporary superconducting qubits include the flux qubit 21 with a large shunting capacitance 22 , the fluxonium 23 and the recently realized 0– π qubit 24 .”
Circuit QED: Superconducting Qubits Coupled to Microwave Photons (2015, methodology): “Recent experiments with the fluxonium qubit design (Manucharyan et al., 2009b) have achieved T1 times exceeding 1 millisecond (Geerlings et al., 2013).”
High-Fidelity, Frequency-Flexible Two-Qubit Fluxonium Gates with a Transmon Coupler (2023, background): “edu The fluxonium qubit [5, 21, 22] is a promising alternative to the transmon for gate-based quantum information processing [23], which alleviates both of these drawbacks.”
Transmon qubit with relaxation time exceeding 0.5 milliseconds (2021, background): “Compared with other superconducting qubits, such as fluxonium[6] and C-shunt flux qubit[7,8], transmon qubit has a simple structure.”
1 / f noise: Implications for solid-state quantum information (2013, background): “ensuring that all superconducting islands are connected to the circuit by at least one large junction (Manucharyan et al., 2009).”
Materials challenges and opportunities for quantum computing hardware (2021, background): “Instead, the issue has so far been addressed through qubit design by adding a large shunting capacitor ( 38 ) or an inductor ( 40 ) to suppress the sensitivity to charge noise.”
Ultrastrong coupling regimes of light-matter interaction (2018, methodology): “Capacitive couplings have been widely used with all types of superconducting qubits engineered so far (Hofheinz et al., 2009; Inomata et al., 2012; Manucharyan et al., 2009; Wallraff et al., 2004).”
High-Coherence Fluxonium Qubit (2018, methodology): “Similar to the original fluxonium design [21], here we attach an external capacitance in the form of a simple dipolar antenna directly to the small junction [Fig.”
Microwave photonics with superconducting quantum circuits (2017, methodology): “by using flux qubits with single [85], three, and four junctions, or the fluxonium qubit [27, 60].”