Silicon, a ubiquitous material in modern computing, is an emerging platform for realizing a source of indistinguishable single-photons on demand. The integration of recently discovered single-photon emitters in silicon into photonic structures is advantageous to exploit their full potential for integrated photonic quantum technologies [1] [2]. Here, we show the integration of telecom photon...
The present poster shows current results we obtained concerning the dynamics of quantum correlations in two noninteractive 2-level atoms coupled to two independently identical thermal reservoirs. The atoms were initially prepared in a Gisin state, which is a mixture of a maximally entangled two-qubit state and a separable mixed state. The quantum entanglement in the evolved Gisin state is...
In this presentation I will show the actual state-of-the-art of our Nitrogen Vacancy center in diamond (NV) platform and develop a theoretical and phenomenological model to evaluate the expressions for the probability p(n,t) that n photons are spontaneously emitted in a given time t by a NV under non-resonant excitation from a 532nm laser and resonant MW radiation. This allows for a better...
Superconductivity in group IV semiconductors is desired for hybrid devices combining both semiconducting and superconducting properties. Following boron-doped diamond and Si, superconductivity has been observed in gallium-doped Ge; however, the obtained specimen is in polycrystalline form [Phys. Rev. Lett. 102, 217003 (2009)]. Here we present superconducting single-crystalline Ge hyperdoped...
Electron spins in Si/SiGe heterostructures are promising for large-scale integration of solid state qubits in a CMOS compatible material system. A key requirement for realizing large arrays of qubits with shared gate control is a high degree of homogeneity of the strain in the Si quantum well (QW) hosting the qubits. Local inhomogeneities in the crystal lattice affect the band structure the QW...
Hybrid systems consisting of semiconductor channels and superconducting elements allow the formation of Andreev qubits and are therefore among the novel material platforms which could pave the way to scalable quantum computation. A key ingredient to achieve high coherence time and strong qubit-qubit coupling is the establishment of a clean superconductor / low-D semiconductor interface and...
We analyse the implementation of a fast nonadiabatic CZ-gate through the resonance between the $|11\rangle$ and $|20\rangle$ states of transmon qubits with tunable coupling. We explicitly derive an effective Hamiltonian for the low-energy eigenstates. This allows us to identify different sources of error and design controls based on the theory of dynamical invariants, which has been proven to...
Complex oxides host a multitude of novel phenomena in condensed matter physics, such as various forms of multiferroicity, colossal magnetoresistance, quantum magnetism and superconductivity. Defect engineering via ion irradiation can be a useful knob to control these physical properties for future practical applications. Two prominent effects are disorder and uniaxial strain. Particularly, the...
