Coherent dynamics of a flux qubit coupled to a harmonic oscillator

By I. Chiorescu, P. Bertet, K. Semba, Yasunobu Nakamura, C. Harmans, J. Mooij. Nature, 2004

598 citations recorded by the source corpus.

In the emerging field of quantum computation and quantum information, superconducting devices are promising candidates for the implementation of solid-state quantum bits (qubits). Single-qubit operations, direct coupling between two qubits and the realization of a quantum gate have been reported. However, complex manipulation of entangled states—such as the coupling of a two-level system to a quantum harmonic oscillator, as demonstrated in ion/atom-trap experiments and cavity quantum electrodynamics—has yet to be achieved for superconducting devices. Here we demonstrate entanglement between a superconducting flux qubit (a two-level system) and a superconducting quantum interference device (SQUID). The latter provides the measurement system for detecting the quantum states; it is also an effective inductance that, in parallel with an external shunt capacitance, acts as a harmonic oscillator. We achieve generation and control of the entangled state by performing microwave spectroscopy and detecting the resultant Rabi oscillations of the coupled system.

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

View Paper: https://www.semanticscholar.org/paper/4059eaa0b24068462b1e632ee4f3bfd5bde0a8a7

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Citations in the corpus

Colloquium: Stimulating uncertainty: Amplifying the quantum vacuum with superconducting circuits (2011, background): “, 2010) has also inspired theoretical and experimental investigations of quantum optics in the microwave regime (Chiorescu et al., 2004; Wallraff et al., 2004; Houck et al., 2007; Schuster et al., 2007; Hofheinz et al., 2009).”
Atomic physics and quantum optics using superconducting circuits (2011, methodology): “For the cavity, a single-mode LC resonator [15] and a multi-mode coplanar waveguide resonator [16] have been used.”
Strong Coupling Cavity QED with Gate-Defined Double Quantum Dots Enabled by a High Impedance Resonator (2017, background): “The strong coupling limit of cavityQEDhas been reached with a multitude of physical systems including alkali atoms [2], Rydberg atoms [3], superconducting circuits [4,5], and optical transitions in semiconductor quantum dots [6,7].”
Fabrication and characterization of superconducting circuit QED devices for quantum computation (2004, unknown): “Our circuit quantum electrodynamics architecture [4], in which a superconducting charge qubit, the Cooper pair box (CPB) [5], is coupled strongly to a coplanar transmission line resonator, has great prospects both for performing quantum optics experiments [6] in solids and for realizing elements for”
Resolving photon number states in a superconducting circuit (2006, background): “achieved with superconducting circuits[8, 12, 27] and approached in semiconducting quantum dots[22, 29].”
Microwave photonics with superconducting quantum circuits (2017, methodology): “However, flux-qubit circuits based on three junctions [32, 33, 38] enable a reduction of the loop size while retaining”
Hybrid quantum circuits: Superconducting circuits interacting with other quantum systems (2012, methodology): “Such flux qubit-resonator systems have been experimentally demonstrated and vacuum Rabi oscillations have also been observed in experiment (Chiorescu et al., 2004; Johansson et al., 2006), where a threejunction flux qubit is enclosed by a SQUID that is inductively coupled to the qubit.”
Multiphoton quantum Rabi oscillations in ultrastrong cavity QED (2015, background): “For suitable junctions, the qubit potential landscape is a double-well potential, where the two minima correspond to states with clockwise and counterclockwise persistent currents ±Ip [10,11].”