Vibronic spectroscopy of an artificial molecule

Abstract

With advanced fabrication techniques it is possible to make nanoscale electronic structures that have discrete energy levels. Such structures are called artificial atoms because of analogy with true atoms. Examples of such atoms are quantum dots in semiconductor heterostructures and Josephson-junction qubits. It is also possible to have artificial atoms interacting with each other. This is an artificial molecule in the sense that the electronic states are analogous to the ones in a molecule. In this letter we present a different type of artificial molecule that, in addition to electronic states, also includes the analog of nuclear vibrations in a diatomic molecule. Some of the earlier experiments could be interpreted using this analogy, including qubits coupled to oscillators and qubits driven by an intense field. In our case the electronic states of the molecule are represented by a Josephson-junction qubit, and the nuclear separation corresponds to the magnetic flux in a loop containing the qubit and an LC oscillator. We probe the vibronic transitions, where both the electronic and vibrational states change simultaneously, and find that they are analogous to true molecules. The vibronic transitions could be used for sideband cooling of the oscillator, and we see damping up to sidebands of order 10.

5 pages, 4 figures

References in corpus (14)

• Circuit Quantum Electrodynamics: Coherent Coupling of a Single Photon to a Cooper Pair Box
• Resolving photon number states in a superconducting circuit
• Coherent dynamics of a flux qubit coupled to a harmonic oscillator
• Mach-Zehnder Interferometry in a Strongly Driven Superconducting Qubit
• Single artificial-atom lasing
• Landau-Zener interferometry with superconducting qubits
• Vacuum Rabi oscillations in a macroscopic superconducting qubit LC oscillator system
• Coherence times of dressed states of a superconducting qubit under extreme driving
• Observation of quantum capacitance in the Cooper-pair transistor
• Sideband Transitions and Two-Tone Spectroscopy of a Superconducting Qubit Strongly Coupled to an On-Chip Cavity
• Sisyphus cooling and amplification by a superconducting qubit
• Nondestructive readout for a superconducting flux qubit
• Direct Observation of Josephson Capacitance
• Multiphoton transitions in a macroscopic quantum two-state system

Cited by in corpus (10)

• Microwave photonics with superconducting quantum circuits
• Efficient multiphoton sampling of molecular vibronic spectra on a superconducting bosonic processor
• Quantum systems under frequency modulation
• Enhancing optomechanical coupling via the Josephson effect
• Stark effect and generalized Bloch-Siegert shift in a strongly driven two-level system
• Microwave Control of Atomic Motion in Optical Lattices
• Multiphoton transitions in Josephson-junction qubits (Review Article)
• Probe spectroscopy of quasienergy states
• Current-Phase Relation and Josephson Inductance of Superconducting Cooper Pair Transistor
• Charge qubit driven via the Josephson nonlinearity