Deterministic delivery of remote entanglement on a quantum network

Large-scale quantum networks promise to enable secure communication, distributed quantum computing, enhanced sensing and fundamental tests of quantum mechanics through the distribution of entanglement across nodes. Moving beyond current two-node networks requires the rate of entanglement generation between nodes to exceed their decoherence rates. Beyond this critical threshold, intrinsically probabilistic entangling protocols can be subsumed into a powerful building block that deterministically provides remote entangled links at pre-specified times. Here we surpass this threshold using diamond spin qubit nodes separated by 2 metres. We realise a fully heralded single-photon entanglement protocol that achieves entangling rates up to 39 Hz, three orders of magnitude higher than previously demonstrated two-photon protocols on this platform. At the same time, we suppress the decoherence rate of remote entangled states to 5 Hz by dynamical decoupling. By combining these results with efficient charge-state control and mitigation of spectral diffusion, we are able to deterministically deliver a fresh remote state with average entanglement fidelity exceeding 0.5 at every clock cycle of $\sim$100 ms without any pre- or post-selection. These results demonstrate a key building block for extended quantum networks and open the door to entanglement distribution across multiple remote nodes.Comment: v2 - updated to include relevant citatio

The effect of Anavidin on <i> Rhodococcus qingshengii</i> VKM Ac-2784D depending on the carbon source in the cultivation medium

Background. Microorganisms have significant plasticity, therefore, the effectiveness of the use of disinfectants is due to the conditions of their use. This is because microorganisms, depending on their habitat, may have different resistance to the same active substance.The aim. To study the effect of Anavidin-Complit on the growth and biofilm formation of Rhodococcus qingshengii VKM Ac-2784D, depending on the carbon source in the cultivation medium.Materials and methods. R. qingshengii VK MAc-2784D was used in the work, the studies were carried out on a mineral nutrient medium 8E, into which 0.5 % glucose, inositol or naphthalene was added as a carbon source. Anavidin was used at a final concentration of 0.08, 0.04, 0.02, 0.01 and 0.005 %. Growth and biofilm formation were evaluated by standard microbiological methods.Results. The disinfecting effect of Anavidin-Complit on the growth of the planktonic form of R. qingshengii VKM Ac-2784D depends on the carbon source. If in a starvation cultivation medium, all concentrations of Anavidin-Complit had an adverse effect on bacteria throughout the experiment, then in the presence of glucose, the adverse effect of low concentrations of Anavidin-Complit decreased by the end of the experiment. In the medium with naphthalene, on the contrary, on the first or second day of cultivation, low concentrations of Anavidin-Complit had a stimulating effect. Anavidin-Complit, depending on the concentration, suppressed the formation of a biofilm on all cultivation media. Microscopy of the biofilm in some cases revealed dense rounded formations consisting of several layers of cells.Conclusion. Thus, in order to increase the effectiveness of disinfectants, a deeper study of the physiological response of microorganisms is necessary, taking into account their living conditions

Analisis Kapasitas Ruang Udara Medan East TMA Setelah Implementasi Rute PBN (RNAV1)

Ruang udara terdiri atas beberapa sektor dengan keterbatasan atau kapasitas yang tentunya berbeda-beda. Hal ini dapat dipengaruhi banyak faktor yang kemudian dapat mempengaruhi optimalisasi ruang udara tersebut. Kapasitas sistem ATC dengan beban kerja sebagai indikator yang diperhituangkan, menjadi salah satu faktor yang difokuskan dalam menganalisis kapasitas ruang udara pada penelitian ini. Metode yang digunakan dalam penelitian ini adalah Pessimistic Sector Capacity. Metode ini mengadopsi Document Eurocontrol Experiment Center (EEC) Note no.21/23 yang merupakan pengembangan metode regresi ATC Capacity Analyser Tool (CAPAN) untuk menghitung kapasitas sebuah sektor serta menganalisis regresi beban kerja petugas ATC dibandingkan dengan jumlah penerbangan pada suatu sektor. Data primer pada penelitian ini diperoleh melalui survei langsung terhadap kegiatan ATC yaitu saat memberikan pelayanan lalu lintas penerbangan pada suatu sektor ruang udara selama 1 jam pada saat peak hours dalam kurun waktu 30 hari. Data sekunder yang diperlukan untuk mendukung analisis yaitu terkait jumlah penerbangan saat jam puncak, kondisi cuaca, dan rencana penerbangan. Hasil penelitian menunjukkan, setelah diimplementasikannya PBN (RNAV1), terdapat peningkatan nilai kapasitas ruang udara di sektor Medan East TMA dari 22 traffic/jam menjadi 25 traffic/jam. Selanjutnya, analisis ini dapat dijadikan baseline guna peningkatan kapasitas ruang udara di masa yang akan datang dalam rangka antisipasi permintaan lalu lintas penerbangan yang terus meningkat

Telecom-Band Quantum Interference of Frequency-Converted Photons from Remote Detuned NV Centers

Entanglement distribution over quantum networks has the promise of realizing fundamentally new technologies. Entanglement between separated quantum processing nodes has been achieved on several experimental platforms in the past decade. To move toward metropolitan-scale quantum network test beds, the creation and transmission of indistinguishable single photons over existing telecom infrastructure is key. Here, we report the interference of photons emitted by remote spectrally detuned NV-center-based network nodes, using quantum frequency conversion to the telecom L band. We find a visibility of 0.79±0.03 and an indistinguishability between converted NV photons around 0.9 over the full range of the emission duration, confirming the removal of the spectral information present. Our approach implements fully separated and independent control over the nodes, time multiplexing of control and quantum signals, and active feedback to stabilize the output frequency. Our results demonstrate a working principle that can be readily employed on other platforms and shows a clear path toward generating metropolitan-scale solid-state entanglement over deployed telecom fibers.QuTechQID/Hanson LabQN/vanderSarlabQID/Taminiau LabQID/Software GroupBUS/TNO STAFFQN/Hanson La