A5081621527- Quantum Information and Cryptography
- Semiconductor Quantum Structures and Devices
- Quantum and electron transport phenomena
- Photonic and Optical Devices
- Quantum optics and atomic interactions
- Quantum Computing Algorithms and Architecture
- Semiconductor Lasers and Optical Devices
- Advanced Semiconductor Detectors and Materials
- Laser-Matter Interactions and Applications
- Mechanical and Optical Resonators
- Neural Networks and Reservoir Computing
- Quantum Dots Synthesis And Properties
- Plasmonic and Surface Plasmon Research
- Magneto-Optical Properties and Applications
- Photonic Crystals and Applications
- Spectroscopy and Quantum Chemical Studies
- Terahertz technology and applications
University of Würzburg
2023-2025
Technion – Israel Institute of Technology
2018-2025
Sapienza University of Rome
2023
Johannes Kepler University of Linz
2023
Abstract Polarized , and unpolarized emission from a single emitter embedded in single, cylindrically symmetric device design is presented. The polarization stems position offset of the with respect to cavity center, which breaks cylindrical symmetry, position‐dependent coupling frequency degenerate eigenmodes resonator structure shown. experimental results are interpreted by using numerical simulations mapping polarization‐resolved far‐field patterns. findings can be generalized any...
Two-photon interference from an InAs/InAlGaAs quantum dot (QD) emitting in the telecom C-band with a raw two-photon visibility of $V_{HOM}=(71.9\pm0.2)$ % is demonstrated. This achieved by two-fold approach: improvement molecular beam epitaxial growth for better QDs, and integration QDs into optical circular Bragg grating resonator Purcell enhancement radiative decay rate. The properties fabricated device are studied means time-correlated single-photon counting under quasi-resonant...
Abstract Purcell‐enhanced quantum dot single‐photon emission in the telecom C‐band from InAs dots inside circular Bragg grating cavities is shown. The are grown by means of molecular beam epitaxy on an InP substrate and embedded into a quaternary In 0.53 Al 0.23 Ga 0.24 As membrane structure. post‐growth flip‐chip process with subsequent removal electron beam‐lithography, (“bullseye”) resonators defined. Micro‐photoluminescence studies devices at cryogenic temperatures K reveal individual...
Abstract Generating single photons in the telecommunication wavelength range from semiconductor quantum dots (QDs) and interfacing them with spins of electrons or holes is high interest recent years, research mainly focusing on indium‐based QDs. However, there not much data optical spin properties gallium antimonide (GaSb) QDs, despite it being a physically rich system an indirect to direct bandgap crossover telecom range. This work investigates (quantum‐) GaSb which are fabricated by...
In principle, the use of entangled photons provides enhanced precision in optical phase measurements. This significantly surpasses classical shot-noise limit, and thereby has many possible applications science technology. practice, however, multiphoton states have been generated so far using various intrinsically probabilistic unscalable processes, counteracting advantages that photon might have. The authors overcome these limitations here by a quantum knitting machine, based on single...
It may be possible to create a confined electronic spin qubit with long coherence time in semiconductor quantum dot, greatly increasing the utility of dots as light-matter interfaces information processing applications.
Semiconductor quantum dots are probably the preferred choice for interfacing anchored, matter spin qubits and flying photonic qubits. While full tomography of a qubit or light polarization is in general straightforward, challenging resource-consuming task. Here we present novel all-optical method conducting quantum-dot-confined spins. Our applicable electronic configurations such as conduction-band electron, valence-band hole, electron-hole pairs bright dark exciton. We excite using short...
We present polarized |S|=0.99$\pm$0.01, and unpolarized |S|=0.03$\pm$0.01 emission from a single emitter embedded in single, cylindrically symmetric device design. show that the polarization stems position offset of with respect to cavity center, which breaks cylindrical symmetry, position-dependent coupling frequency degenerate eigenmodes resonator structure. The experimental results are interpreted by using numerical simulations mapping polarization-resolved far-field patterns. Our...
We present a method for quantum tomography of multiqubit states. apply the to spin-multiphoton states, which we generate using dot based device. Periodic excitation confined spin deterministically generates strings entangled photons in cluster state, threefold faster than previously demonstrated. Our uses time-resolved polarization-sensitive multiphoton correlation measurements measure both polarization and that emitted photons. develop an edge-sensitive gradient-descent algorithm it...
Creating single photons in the telecommunication wavelength range from semiconductor quantum dots (QDs) and interfacing them with spins of electrons or holes has been high interest recent years, research mainly focusing on indium based QDs. However, there is not much data optical spin properties galliumantimonide (GaSb) QDs, despite it being a physically rich system an indirect to direct bandgap crossover telecom range. Here, we investigate (quantum-) GaSb dots, which are fabricated by...
We present magneto-optical studies of a self-assembled semiconductor quantum dot, concentrating specifically on the case in which dot is doubly positively charged, studying this way confined hole - exchange interaction. A simple harmonic potential model, we extend to capture influence an externally applied magnetic field Faraday configuration fully describe observed polarization sensitive magneto-photoluminscence spectra. deduce effective composition from its measured electronic g-factor....
We use a multiphoton Greenberger-Horne-Zeilinger state to demonstrate optical phase measurement with sensitivity that beats the standard quantum limit. The is produced deterministically at rate of 76 MHz from single point source.
We use a multiphoton Greenberger-Horne-Zeilinger state to demonstrate optical phase measurement with sensitivity that beats the standard quantum limit. The is produced deterministically at rates which exceed 300 MHz from single point source.
On demand generated Noon state is used for optical phase measurement with precision which better than the standard noise limit, depending only on detectors’ efficiency.
We present a novel method for quantum tomography of multi-qubit states. apply the to spin-multi-photon states, which we produce by periodic excitation semiconductor quantum-dot- confined spin every 1/4 its coherent precession period. These timed excitations lead deterministic generation strings entangled photons in cluster state. show that our can be used characterizing process map, produces photonic cluster. From measured quantify robustness entanglement The 3-fold enhanced rate over...