A5029435164- Quantum optics and atomic interactions
- Quantum Information and Cryptography
- Cold Atom Physics and Bose-Einstein Condensates
- Quantum Mechanics and Applications
- Photonic and Optical Devices
- Mechanical and Optical Resonators
- Semiconductor Lasers and Optical Devices
- Atomic and Subatomic Physics Research
- Advanced Frequency and Time Standards
- Advanced Fiber Laser Technologies
- Advanced Thermodynamics and Statistical Mechanics
- Semiconductor Quantum Structures and Devices
- Quantum Dots Synthesis And Properties
- Quantum Electrodynamics and Casimir Effect
- Neural Networks and Reservoir Computing
Humboldt-Universität zu Berlin
2012-2023
Controlling coherent interaction between optical fields and quantum systems in scalable, integrated platforms is essential for technologies. Miniaturised, warm alkali-vapour cells with on-chip photonic devices represent an attractive system, particular delay or storage of a single-photon state. Hollow-core fibres planar waveguides are widely used to confine light over long distances enhancing light-matter atomic-vapour cells. However, they suffer from inefficient filling times, enhanced...
Hybrid interfaces between distinct quantum systems play a major role in the implementation of networks. Quantum states have to be stored memories synchronize photon arrival times for entanglement swapping by projective measurements repeaters or purification. Here, we analyze distortion single wave packet propagating through dispersive and absorptive medium with high spectral resolution. Single photons are generated from In(Ga)As dot its excitonic transition precisely set relative Cesium D1...
We present an efficient and robust source of photons at the $^{87}$Rb D1-line (795 nm) with a narrow bandwidth $\delta=226(1)$ MHz. The is based on non-degenerate, cavity-enhanced spontaneous parametric down-conversion in monolithic optical oscillator far below threshold. setup allows for coupling to single mode fibers. A heralding efficiency $\eta_{\mathrm{heralded}}=45(5)$ % achieved, uncorrected number detected photon pairs $3.8 \times 10^{3}/(\textrm{s mW})$. For pair generation rates up...
The authors report single-photon emission from InGaAs quantum dots grown by droplet epitaxy on (100) GaAs substrates using a solid-source molecular beam system at elevated substrate temperatures above 400°C without post-growth annealing. High-resolution micro-photoluminescence spectroscopy exhibits sharp excitonic emissions with lifetimes ranging 0.7 to 1.1 ns. coherence properties of the emitted photons are investigated measuring first-order field correlation function.
Future quantum networks require a hybrid platform of dissimilar systems. Within the platform, joint states have to be mediated either by single photons, photon pairs or entangled pairs. The wavelength has lie within telecommunication band enable long-distance fibre transmission. In addition, temporal shape photons needs tailored efficiently match involved Altogether, this requires efficient coherent wavelength-conversion arbitrarily shaped single-photon wave packets. Here, we demonstrate...
Abstract We demonstrate a two-color entangled photon pair source which can be adapted easily to wide range of wavelength combinations. A Fresnel rhomb as geometrical quarter-wave plate and versatile combination compensation crystals are key components the source. Entanglement two photons at Cs D1 line (894.3 nm) telecom O-band (1313.1 with fidelity $$F=0.753 \pm 0.021$$ <mml:math xmlns:mml="http://www.w3.org/1998/Math/MathML"> <mml:mrow> <mml:mi>F</mml:mi> <mml:mo>=</mml:mo>...
Abstract Quantum theory stipulates that if two particles are identical in all physical aspects, the allowed states of system either symmetric or antisymmetric with respect to permutations particle labels. Experimentally, symmetry can be inferred indirectly from fact neglecting correct exchange theoretical analysis leads dramatic discrepancies observations. The only way directly unveil for, say, is through interference two-particle state and physically permuted one, measuring phase associated...
We introduce components for future quantum hybrid networks. A tailored narrow-band photon pair source, tunable emission of Fourier-limited photons from a dot, and single frequency conversion to the telecom C-band are demonstrated.
Quantum-optical experiments situated in a gravitationally bound experimental setup are fundamentally limited numerous ways, such as the gravitational sag experienced by trapped atoms or free-evolution times of an atomic interferometer.These constraints can be overcome deploying experiment microgravity platform, International Space Station (ISS).The Bose-Einstein Condensate and Cold Atom Laboratory (BECCAL), collaboration between NASA DLR successor to NASA's CAL mission, aims achieve just...
In forthcoming quantum networks various systems might be involved to accomplish individual tasks, including storage of states, logic operations, error correction, or entanglement distillation. An interface between a single photon emitter and potential could provide one fundamental building block such hybrid system. Semiconductor dots (QD) atomic vapors have already been brought together by spectroscopy cesium rubidium [1,2], narrow filtering QD resonance fluorescence in [3], slowing down...
Quantum communication would enable opportunities such as secure [1]. A quantum network with nodes and channels is necessary for this. The realization of a requires the ability to process, store send photons over long distances. It not very likely that single physical system can accomplish all these operations. Therefore, dissimilar systems have be connected in future networks.
Quantum memories are an essential ingredient for quantum repeaters [1] and enabler advanced optical simulators [2].
It is widely accepted that photons are bosons. To the best of our knowledge, we present first-ever test this fundamental assumption quantum electrodynamics and discuss influence experimental imperfections.
On-chip hollow-core waveguides represent a promising platform for microfluidic analysis, nonlinear optics and quantum information processing, due to light guidance directly inside the medium of interest. Recently, we have reported 3D printed waveguide ⎯ cage which consists ring high-aspect-ratio cylinders combines high fraction field in core (>99%) with transverse access. Here will discuss our results on interfacing cages optical fibers, measurement electromagnetically induced transparency...
Quantum memories are a key tool for optical quantum information processing. Several physical implementations have been suggested. Photonic nano- and microstructures can significantly improve light matter interaction in this way facilitate efficient photon storage. In presentation we will introduce photonics cage as an engineered photonic structure to the performance of based on warm atomic (Cs) vapor. Based first results derive improved storage parameters such device discuss prospect...