A. N. Sultanov

Mollow triplet through pump-probe single-photon spectroscopy of artificial atoms

We analyze a photon transport through an 1D open waveguide side coupled to the

Narrow bandpass cryogenic filter for microwave measurements

N

Measurement of the superconducting flux qubit parameters in the quasi-dispersive regime

-photon microwave cavity with embedded artificial two- level atom (qubit). The qubit state is probed by a weak signal at the fundamental frequency of the waveguide. Within the formalism of projection operators and non-Hermitian Hamiltonian approach we develop a one-photon approximation scheme to obtain the photon wavefunction which allows for the calculation of the probability amplitudes of the spontaneous transitions between the levels of two Rabi doublets in

Spectroscopy of a superconducting flux qubit in a quasidispersive mode

N

Transfer of excited state between two qubits in an open waveguide

- photon cavity. We obtain analytic expressions for the transmission and reflection factors of the microwave signal through a waveguide, which contain the information of the qubit parameters. We show that for small number of cavity photons the Mollow spectrum consists of four spectral lines which is a direct manifestation of quantum nature of light. The results obtained in the paper are of general nature and can be applied to any type of qubits. The specific properties of the qubit are only encoded in the two parameters: the energy

Effect of the qubit relaxation on transport properties of microwave photons

\Omega

Scattering of a single photon on a two-qubit structure with resonators

of the qubit and its coupling

Influence of the nonradiative decay of qubits into a common channel on the transport properties of microwave photons

\lambda

Transport properties of a microwave photon in a system with two artificial atoms

to the cavity photons.

Microwave characterization of nanomechanical resonator

An ultra-wide stopband hairpin bandpass filter with integrated nonuniform transmission lines was designed and fabricated for highly sensitive measurements at cryogenic temperatures down to millikelvin and a frequency range of 10 Hz-10 GHz. The scattering matrices of the filter were characterized at T = 4.2 K. The filter provides a stopband from 10 Hz to 2.2 GHz and from 2.3 GHz to 10 GHz with more than 50 dB and 40 dB of amplitude suppression, respectively. The center frequency of the passband is f0 = 2.25 GHz with a bandwidth Δf = 80 MHz. The maximum insertion loss in the passband is 4 dB. The filter has a 50 Ω input and output impedance, SubMiniature version A connector termination, and significantly reduced form factor. The wide stopband frequency range and narrow passband in conjunction with small dimensions make the filter suitable to use it as a part of a high sensitive readout for superconducting quantum circuits, such as superconducting quantum bits and cryogenic parametric amplifiers.