Related papers: Low-frequency spectroscopy for quantum multi-level…
We investigate phase-sensitive interference effects in a periodically $\sin(2\pi f_{\rm rf} t)$-driven, artificial two-state system connected to a microwave resonator at $f_{LC} \simeq 800$ MHz. We observe two kinds of multiphoton…
We study the time-resolved fluorescence spectrum in two-level systems interacting with an incident coherent field, both in the weak and intermediate coupling regimes. For a single two-level system in the intermediate coupling case, as time…
We have observed multi-photon resonances in a system with a spin 3/2 irradiated simultaneously by a multiple pulse radiofrequency sequence and a low frequency field swept in the range 0-80 kHz. The used excitation scheme allowed us to…
We investigate the quantum interference induced shifts between energetically close states in highly charged ions, with the energy structure being observed by laser spectroscopy. In this work, we focus on hyperfine states of lithiumlike…
We exploit the concept of Landau-Zener transitions at avoided energy crossings as a quantum-control tool. In an avoided crossing the two quantum states interchange their characteristics as an external parameter is varied. Depending on the…
We investigate experimentally and theoretically the interference at avoided crossings which are repeatedly traversed as a consequence of an applied ac field. Our model system is a charge qubit in a serial double quantum dot connected to two…
The effect of the laser linewidth on the resonance fluorescence spectrum of a two-level atom is revisited. The novel spectral features, such as hole-burning and dispersive profiles at line centre of the fluorescence spectrum are predicted…
The degenerate Landau-Zener-Majorana-St\"uckelberg model consists of two degenerate energy levels whose energies vary with time and in the presence of an interaction which couples the states of the two levels. In the adiabatic limit, it…
Landau-Zener-St\"uckelberg (LZS) interference of continuously driven superconducting qubits is studied. Going beyond the second order perturbation expansion, we find a time dependent stationary population evolution as well as unsymmetrical…
Superconducting circuit quantum electrodynamics (QED) architecture composed of superconducting qubit and resonator is a powerful platform for exploring quantum physics and quantum information processing. By employing techniques developed…
In this paper, we generalized the quantum frequency mixing technology to a ladder-type four-level system and studied its effect on electromagnetically induced transparency spectra. We found a secondary splitting of Autler-Townes splitting…
We study Landau-Zener-Stuckelberg (LZS) interferometry in multilevel systems coupled to an Ohmic quantum bath. We consider the case of superconducting flux qubits driven by a dc+ac magnetic fields, but our results can apply to other similar…
Quantum control of the wave function of two interacting electrons confined in quasi-one-dimensional double-well semiconductor structures is demonstrated. The control strategies are based on the knowledge of the energy spectrum as a function…
We discuss quantum interference effects in a three-level atom in lambda-configuration, where both transitions from the upper state to the lower states are driven by a single monochromatic laser field. Although the system has two lower…
We demonstrate amplification (and attenuation) of a probe signal by a driven two-level quantum system in the Landau-Zener-St\"{u}ckelberg-Majorana regime by means of an experiment, in which a superconducting qubit was strongly coupled to a…
We report experimental observations of interference between three-photon and one-photon excitations, and phase control of light attenuation/transmission in a four-level system. Either constructive interference or destructive interference…
When the level separation of a qubit is modulated periodically across an avoided crossing, tunneling to the excited state - and consequently Landau-Zener-St\"uckelberg interference - can occur. The types of modulation studied so far…
The coherent dynamics of a quantum mechanical two-level system passing through an anti-crossing of two energy levels can give rise to Landau-Zener-St\"uckelberg-Majorana (LZSM) interference. LZSM interference spectroscopy has proven to be a…
We demonstrate Mach-Zehnder-type interferometry in a superconducting flux qubit. The qubit is a tunable artificial atom, whose ground and excited states exhibit an avoided crossing. Strongly driving the qubit with harmonic excitation sweeps…
The device for the Josephson flux qubit (DJFQ) can be considered as a solid state artificial atom with multiple energy levels. When a large amplitude harmonic excitation is applied to the system, transitions at the energy levels avoided…