7 research outputs found
Collective Excitation of Spatio-Spectrally Distinct Quantum Dots Enabled by Chirped Pulses
For a scalable photonic device producing entangled photons, it is desirable
to have multiple quantum emitters in an ensemble that can be collectively
excited, despite their spectral variability. For quantum dots, Rabi rotation,
the most popular method for resonant excitation, cannot assure a universal,
highly efficient excited state preparation, because of its sensitivity to the
excitation parameters. In contrast, Adiabatic Rapid Passage (ARP), relying on
chirped optical pulses, is immune to quantum dot spectral inhomogeneity. Here,
we advocate the robustness of ARP for simultaneous excitation of the biexciton
states of multiple quantum dots. For positive chirps, we find that there is
also regime of phonon advantage that widens the tolerance range of spectral
detunings. Using the same laser pulse we demonstrate the simultaneous
excitation of energetically and spatially distinct quantum dots. Being able to
generate spatially multiplexed entangled photon pairs is a big step towards the
scalability of photonic devices
Compact Chirped Fiber Bragg Gratings for Single-Photon Generation from Quantum Dots
A scalable source of single photons is a key constituent of an efficient
quantum photonic architecture. To realize this, it is beneficial to have an
ensemble of quantum emitters that can be collectively excited with high
efficiency. Semiconductor quantum dots hold great potential in this context,
due to their excellent photophysical properties. Spectral variability of
quantum dots is commonly regarded as a drawback introduced by the fabrication
method. However, this is beneficial to realize a frequency-multiplexed
single-photon platform. Chirped pulse excitation, relying on the so-called
adiabatic rapid passage, is the most efficient scheme to excite a quantum dot
ensemble due to its immunity to individual quantum dot parameters. Yet, the
existing methods of generating chirped laser pulses to excite a quantum emitter
are bulky, lossy, and mechanically unstable, which severely hampers the
prospects of a quantum dot photon source. Here, we present a compact, robust,
and high-efficiency alternative for chirped pulse excitation of solid-state
quantum emitters. Our simple plug-and-play module consists of chirped fiber
Bragg gratings (CFBGs), fabricated via femtosecond inscription, to provide high
values of dispersion in the near-infrared spectral range, where the quantum
dots emit. We characterize and benchmark the performance of our method via
chirped excitation of a GaAs quantum dot, establishing high-fidelity
single-photon generation. Our highly versatile chirping module coupled to a
photon source is a significant milestone toward realizing practical quantum
photonic devices
Tanggung Jawab Hukum Atas Kejahatan Korporasi
AbstrakDengan diakuinya korporasi sebagai subyek hukum pidana berarti korporasi dapat dipertanggung jawabkan dalam hukum pidana, korporasi itu sifatnya bukan badaniah atau orang oleh karena itu tidak bisa dikurung yang bisa dipenjara itu adalah orang-orang didalamnya. Pidana yang harus digunakan adalah pidana denda, namun juga harus ada pidana-pidana lain yang bisa membuat korporasi tidak lagi mengulang kesalahannya. pengertian Tindak Pidana oleh Korporasi sebagaimana diatur dalam Pasal 3 Peraturan MA RI 13/2016 sesuai kutipan berikut: “Tindak pidana oleh Korporasi merupakan tindak pidana yang dilakukan oleh orang berdasarkan hubungan kerja, atau berdasarkan hubungan lain, baik sendiri-sendiri maupun bersama-sama yang bertindak untuk dan atas nama Korporasi di dalam maupun di luar Lingkungan Korporasi.Kata Kunci: Kejahatan Korporasi, Tanggung Jawab Hukum AbstractThe recognition of corporations as subjects of criminal law means that corporations can be accounted for in criminal law, corporations are not physical in nature or people, therefore they cannot be imprisoned, it is the people in them. The punishment that must be used is a fine, but there must also be other crimes that can make the corporation no longer repeat its mistakes. the definition of Crime by Corporations as regulated in Article 3 of MA RI Regulation 13/2016 according to the following quote: “Criminal acts by corporations are criminal acts committed by people based on work relationships, or based on other relationships, either individually or jointly act for and on behalf of the Corporation inside and outside the Corporate Environment.Keywords: Corporate crime, legal responsibilit
Fast and efficient demultiplexing of single photons from a quantum dot with resonantly enhanced electro-optic modulators
We report on a multi-photon source based on active demultiplexing of single
photons emitted from a resonantly excited GaAs quantum dot. Active
temporal-to-spatial mode demultipexing is implemented via resonantly enhanced
free-space electro-optic modulators, making it possible to route individual
photons at high switching rates of 38 MHz. We demonstrate routing into four
spatial modes with a high end-to-end efficiency of 79% and measure a
four-photon coincidence rate of 0.17 Hz mostly limited by the single-photon
source brightness and not by the efficiency of the demultiplexer itself. We use
the demultiplexer to characterize the pairwise indistinguishability of
consecutively emitted photons from the quantum dot with variable delay time.Comment: The supplementary material is included as ancillary fil
Evaluation Of Central Nervous System In Patients With Glycogen Storage Disease Type 1A
We aimed to evaluate structure and functions of central nervous system (CNS) in children with glycogen storage disease (GSD) type 1a. Neurological examination, psychometric tests, electroencephalography (EEG), magnetic resonance imaging (MRI), visual evoked potentials (VEP) and brainstem auditory evoked potentials (BAEP) were performed. The results were compared between patients with good and poor metabolic control and healthy children. Twenty-three patients with GSD type 1a were studied. Twelve patients were in poor metabolic control group and 11 patients in good metabolic control group. Five patients had intellectual disability, 10 had EEG abnormalities, seven had abnormal VEP and two had abnormal BAEP results. MRI was abnormal in five patients. There was significant correlation between the number of hypoglycemic attacks and MRI abnormalities. Central nervous system may be affected in GSD type 1a even in patients with normal neurologic examination. Accumulation of abnormal results in patients with poor metabolic control supports the importance of metabolic control in GSD type 1a.WoSScopu
Controlling the photon number coherence of solid-state quantum light sources for quantum cryptography
Abstract Quantum communication networks rely on quantum cryptographic protocols including quantum key distribution (QKD) based on single photons. A critical element regarding the security of QKD protocols is the photon number coherence (PNC), i.e., the phase relation between the vacuum and one-photon Fock state. To obtain single photons with the desired properties for QKD protocols, optimal excitation schemes for quantum emitters need to be selected. As emitters, we consider semiconductor quantum dots, that are known to generate on-demand single photons with high purity and indistinguishability. Exploiting two-photon excitation of a quantum dot combined with a stimulation pulse, we demonstrate the generation of high-quality single photons with a controllable degree of PNC. The main tuning knob is the pulse area giving full control from minimal to maximal PNC, while without the stimulating pulse the PNC is negligible in our setup for all pulse areas. Our approach provides a viable route toward secure communication in quantum networks