In the past 20 years, impressive progress has been made both experimentally and
theoretically in superconducting quantum circuits, which provide a platform for manipulating …

We present spectroscopic measurements of the Autler-Townes doublet and the sidebands of
the Mollow triplet in a driven superconducting qubit. The ground to first excited state …

Superconducting qubits, behave as artificial two-level atoms and are used to investigate
fundamental quantum phenomena. In this context, the study of multiphoton excitations …

We demonstrated microwave-induced cooling in a superconducting flux qubit. The thermal
population in the first-excited state of the qubit is driven to a higher-excited state by way of a …

The energy-level structure of a quantum system, which has a fundamental role in its
behaviour, can be observed as discrete lines and features in absorption and emission …

We introduce a systematic formalism for two-resonator circuit QED, where two on-chip
microwave resonators are simultaneously coupled to one superconducting qubit. Within this …

We present experiments on the driven dynamics of a two-level superconducting artificial
atom. The driving strength reaches 4.78 GHz, significantly exceeding the transition …

In order to gain a better understanding of the origin of decoherence in superconducting flux
qubits, we have measured the magnetic field dependence of the characteristic energy …

Quantum optimal control theory allows us to design accurate quantum gates. We employ it to
design high-fidelity two-bit gates for Josephson charge qubits in the presence of both …

A new regime of coherent quantum dynamics of a qubit is realized at low driving frequencies
in the strong driving limit. Coherent transitions between qubit states occur via the Landau …