arXiv:1101.5542 · Physical Review Letters

Dynamics of Coherent and Incoherent Emission from an Artificial Atom in a 1D Space

A. A. Abdumalikov, O. V. Astafiev, Yu. A. Pashkin, Yasunobu Nakamura, J. S. Tsai

Published Jul 22, 2011• 68 citations

Abstract

We study dynamics of a two-level superconducting quantum system, analogous to a natural atom in an open space, by measuring the evolution of its coherent and incoherent emission. The emitted waves containing full information about the states of the artificial atom are efficiently collected due to strong atom-transmission-line coupling. This allows us to do simultaneous measurements of all the quantum state projections and perform a full characterization of the system. We derive coherence times and extract the two-time correlation function from the dynamics of the coherent emission.

DOI: 10.1103/physrevlett.107.043604

Related papers

Scattering spectroscopy of a superconducting artificial atom coupled to two half spaces

A. Yu. Dmitriev, A. Korenkov, O. V. Astafiev

We propose a novel approach for spectroscopic characterization of quantum systems. A superconducting quantum system—an artificial atom—is coupled asymmetrically to two open-end transmission lines (1D half-spaces). The lines themselves are strongly decoupled from each other. This results in suppression of the direct microwave propagation from one side to another. The atom, excited from the weaker coupled side relaxes with photon emission preferably to the stronger coupled side. By measuring the emission spectrum, we reconstruct the energy levels of the artificial atom. Our method allows to reject the excitation tone and to detect only the elastically scattered emission corresponding to intra-atomic transitions. We also demonstrate visualization of the higher-level transitions by populating the excited levels. Such a system does not have an optical analog with natural atoms or quantum dots coupled to two half spaces.

Journal of Experimental and Theoretical Physics LettersJan 1, 20171 citation

Evolution of Propagating Coherent Pulses Driving a Single Superconducting Artificial Atom

Andrei Vladimirovich Vasenin, Shamil Kadyrmetov, Aleksey N. Bolgar +2 more

An electromagnetic wave propagating through a waveguide with a strongly coupled two-level superconducting artificial atom exhibits an evolving superposition with the atom. The Rabi oscillations in the atom result from a single excitation-relaxation, corresponding to photon absorption and stimulated emission from and to the field. In this study, we experimentally investigated the time-dependent behavior of the field transmitted through a waveguide with a strongly coupled transmon. The scattered fields agree well with the predictions of the input-output theory. We demonstrate that the time evolution of the propagating fields, because of the interaction, encapsulates all information about the atom. Furthermore, we deduced the dynamics of the incoherent radiation component from the first-order correlation function of the measured field.

arXiv:2309.01563Physical Review LettersAug 14, 20242 citations

Dynamics and resonance fluorescence from a superconducting artificial atom doubly driven by quantized and classical fields

Xinhui Ruan, Jia-Heng Wang, Dong He +11 more

We report an experimental demonstration of resonance fluorescence in a two-level superconducting artificial atom under two driving fields coupled to a detuned cavity. One of the fields is classical and the other is varied from quantum (vacuum fluctuations) to classical by controlling the photon number inside the cavity. The device consists of a transmon qubit strongly coupled to a one-dimensional transmission line and a coplanar waveguide resonator. We observe a sideband anticrossing and asymmetry in the emission spectra of the system through a one-dimensional transmission line, which is fundamentally different from the weak-coupling case. By changing the photon number inside the cavity, the emission spectrum of our doubly driven system approaches the case when the atom is driven by two classical bichromatic fields. We also measure the dynamical evolution of the system through the transmission line and study the properties of the first-order correlation function, Rabi oscillations, and energy relaxation in the system. The study of resonance fluorescence from an atom driven by two fields promotes understanding decoherence in superconducting quantum circuits and may find applications in superconducting quantum computing and quantum networks. Published by the American Physical Society 2024

arXiv:2403.11142Physical Review ResearchJul 15, 20244 citations

Ultimate On-Chip Quantum Amplifier

O. V. Astafiev, A. A. Abdumalikov, Alexandre M. Zagoskin +3 more

We report amplification of electromagnetic waves by a single artificial atom in open 1D space. Our three-level artificial atom--a superconducting quantum circuit--coupled to a transmission line presents an analog of a natural atom in open space. The system is the most fundamental quantum amplifier whose gain is limited by a spontaneous emission mechanism. The noise performance is determined by the quantum noise revealed in the spectrum of spontaneous emission, also characterized in our experiments.

arXiv:1004.3864Physical Review LettersMay 6, 2010116 citations

Spontaneous emission of a three-level artificial atom in a one-dimensional open waveguide

O. A. Chuikin, Ya. S. Greenberg, O. V. Kibis

We study the dynamical and spectral characteristics of a quantum three-level ladder system, interacting with a continuous electromagnetic field in one-dimensional open waveguide. Common realization of such systems is a waveguide QED setup - a superconducting artificial atom (transmon), coupled to an open microwave transmission line. We derive an analytical solution for spontaneous emission of initially excited atom, and use it to study the probability of state detection and spectral density of output photon states. We find that for strong coupling of transmon to a waveguide emitted photons show correlation in frequency and can have the same energies, even if the three-level system is anharmonic.

quant-pharXiv:2511.06291Physica ScriptaNov 11, 20250 citations

Resonance Fluorescence from a two-level artificial atom strongly coupled to a single-mode cavity

Zhihui Peng, He, D., Y. Zhou +8 more

We experimentally demonstrate the resonance fluorescence of a two-level artificial atom strongly coupled to a single-mode cavity field. The effect was theoretically predicted thirty years ago by Savage [Phys. Rev. Lett. 63, 1376 (1989)]. The system consists of a superconducting qubit circuit and a one-dimensional transmission line resonator. In addition, a one-dimensional transmission line strongly coupled to the atom serves as an open space. The effect takes place, when a microwave field is applied to the cavity, which in turn is resonantly coupled to the atom. The fluorescence spectrum is measured via the emission into the transmission line. We find that the central peak is determined by the atom spontaneous emission to the open space and the widths of side peaks are largely determined by the coherent interaction between the atom and the cavity, that is, the fluorescence spectrum here is very different from that of the Mollow triplet. We also derive analytical form for the spectrum. Our experimental results agree well with theoretical calculations.

arXiv:2202.12080Feb 24, 20221 citation