Platelets and Hepatocellular Cancer: Bridging the Bench to the Clinics

Growing interest is recently being focused on the role played by the platelets in favoring hepatocellular cancer (HCC) growth and dissemination. The present review reports in detail both the experimental and clinical evidence published on this topic. Several growth factors and angiogenic molecules specifically secreted by platelets are directly connected with tumor progression and neo-angiogenesis. Among them, we can list the platelet-derived growth factor, the vascular endothelial growth factor, the endothelial growth factor, and serotonin. Platelets are also involved in tumor spread, favoring endothelium permeabilization and tumor cells' extravasation and survival in the bloodstream. From the bench to the clinics, all of these aspects were also investigated in clinical series, showing an evident correlation between platelet count and size of HCC, tumor biological behavior, metastatic spread, and overall survival rates. Moreover, a better understanding of the mechanisms involved in the platelet-tumor axis represents a paramount aspect for optimizing both current tumor treatment and development of new therapeutic strategies against HCC

Multi-Node Quantum Networks with Diamond Qubits

The Internet has revolutionized the way we live. It has enabled applications far beyond what it was originally built for, and it will continue to exceed our expectations for the future. Quantum computers, and the network that will connect them—the Quantum Internet— are likely going to follow the same path. Differently from normal computers, quantum computers can share a property called entanglement, which allows the qubits (quantum bits) to be connected at a much more fundamental level. This property enables a range of new applications that span secure communication to enhanced metrology. Over the past fifteen years, significant progress has been made in connecting rudimentary quantum network nodes via long-distance entanglement. Several quantum platforms have demonstrated entanglement generation between two physically separated qubits. In this thesis we take a significant step forward, both in terms of experimental complexity achieved, and in the abstraction of said complexity for future developments. Moving past two-node experiments required a fundamental redesign of our experimental apparatus, as well as developing the capabilities to control simultaneously the additional node. The first result of this thesis is building a three-node entanglement-based quantum network. We demonstrated distribution of Greenberger-Horne-Zeilinger states over the network, as well as a building block for larger networks: entanglement swapping. Differently from previous multi-node demonstrations, which relied on post-selection, our network is able to perform the entanglement distribution in a heralded fashion: a signal will notify the users that the protocol was successful, and that the state is ready to be used. The second result builds on the first, by adding control over a fifth qubit, improving the quality of the entanglement, and introducing a novel repetitive readout technique, to achieve quantum teleportation of a qubit from the third node to the first—nodes that do not share a direct entanglement channel. The third and final result is the demonstration of entanglement delivery using a quantum network stack. The Internet is built using a plethora of physical platforms: optical fibers, Ethernet cables, Wi-Fi, satellite signals etc. To abstract their functionality, and make applications work regardless of the underlying platform, a layered approach was developed in the 1970s (the Internet protocol). Taking inspiration from classical network stacks, we demonstrate the first two layers of a quantum network stack, the physical layer (where the qubits, lasers and signal generators live), and the link layer, which abstracts the concepts of qubit and entanglement generation such that they can be used by applications at the higher-layers, hiding the complexity of the quantum platform being used.Casimir PhD Series, Delft-Leiden 2021-31QID/Hanson La

Witnessing entanglement in experiments with correlated noise

The purpose of an entanglement witness experiment is to certify the creation of an entangled state from a finite number of trials. The statistical confidence of such an experiment is typically expressed as the number of observed standard deviations of witness violations. This method implicitly assumes that the noise is well-behaved so that the central limit theorem applies. In this work, we propose two methods to analyze witness experiments where the states can be subject to arbitrarily correlated noise. Our first method is a rejection experiment, in which we certify the creation of entanglement by rejecting the hypothesis that the experiment can only produce separable states. We quantify the statistical confidence by a p-value, which can be interpreted as the likelihood that the observed data is consistent with the hypothesis that only separable states can be produced. Hence a small p-value implies large confidence in the witnessed entanglement. The method applies to general witness experiments and can also be used to witness genuine multipartite entanglement. Our second method is an estimation experiment, in which we estimate and construct confidence intervals for the average witness value. This confidence interval is statistically rigorous in the presence of correlated noise. The method applies to general estimation problems, including fidelity estimation. To account for systematic measurement and random setting generation errors, our model takes into account device imperfections and we show how this affects both methods of statistical analysis. Finally, we illustrate the use of our methods with detailed examples based on a simulation of NV centers.QID/Wehner GroupQID/Hanson LabQuTechQN/Hanson LabQuantum Internet DivisionQuantum Information and Softwar

Qubit teleportation between non-neighbouring nodes in a quantum network

Future quantum internet applications will derive their power from the ability to share quantum information across the network1,2. Quantum teleportation allows for the reliable transfer of quantum information between distant nodes, even in the presence of highly lossy network connections3. Although many experimental demonstrations have been performed on different quantum network platforms4–10, moving beyond directly connected nodes has, so far, been hindered by the demanding requirements on the pre-shared remote entanglement, joint qubit readout and coherence times. Here we realize quantum teleportation between remote, non-neighbouring nodes in a quantum network. The network uses three optically connected nodes based on solid-state spin qubits. The teleporter is prepared by establishing remote entanglement on the two links, followed by entanglement swapping on the middle node and storage in a memory qubit. We demonstrate that, once successful preparation of the teleporter is heralded, arbitrary qubit states can be teleported with fidelity above the classical bound, even with unit efficiency. These results are enabled by key innovations in the qubit readout procedure, active memory qubit protection during entanglement generation and tailored heralding that reduces remote entanglement infidelities. Our work demonstrates a prime building block for future quantum networks and opens the door to exploring teleportation-based multi-node protocols and applications2,11–13.Applied SciencesQID/Hanson LabQN/Borregaard GroupQN/Hanson La

Entangling remote qubits using the single-photon protocol: an in-depth theoretical and experimental study

The generation of entanglement between remote matter qubits has developed into a key capability for fundamental investigations as well as for emerging quantum technologies. In the single-photon, protocol entanglement is heralded by generation of qubit-photon entangled states and subsequent detection of a single photon behind a beam splitter. In this work we perform a detailed theoretical and experimental investigation of this protocol and its various sources of infidelity. We develop an extensive theoretical model and subsequently tailor it to our experimental setting, based on nitrogen-vacancy centers in diamond. Experimentally, we verify the model by generating remote states for varying phase and amplitudes of the initial qubit superposition states and varying optical phase difference of the photons arriving at the beam splitter. We show that a static frequency offset between the optical transitions of the qubits leads to an entangled state phase that depends on the photon detection time. We find that the implementation of a Charge-Resonance check on the nitrogen-vacancy center yields transform-limited linewidths. Moreover, we measure the probability of double optical excitation, a significant source of infidelity, as a function of the power of the excitation pulse. Finally, we find that imperfect optical excitation can lead to a detection-arm-dependent entangled state fidelity and rate. The conclusion presented here are not specific to the nitrogen-vacancy centers used to carry out the experiments, and are therefore readily applicable to other qubit platforms.QID/Hanson LabQN/Borregaard groepQN/Hanson La

Realization of a multinode quantum network of remote solid-state qubits

The distribution of entangled states across the nodes of a future quantum internet will unlock fundamentally new technologies. Here, we report on the realization of a three-node entanglement-based quantum network. We combine remote quantum nodes based on diamond communication qubits into a scalable phase-stabilized architecture, supplemented with a robust memory qubit and local quantum logic. In addition, we achieve real-time communication and feed-forward gate operations across the network. We demonstrate two quantum network protocols without postselection: the distribution of genuine multipartite entangled states across the three nodes and entanglement swapping through an intermediary node. Our work establishes a key platform for exploring, testing, and developing multinode quantum network protocols and a quantum network control stack.Accepted Author ManuscriptQuTechQID/Hanson LabGeneralBUS/Quantum DelftQID/Wehner GroupQuantum Internet DivisionQuantum Information and SoftwareQN/Hanson La

A link layer protocol for quantum networks

Quantum communication brings radically new capabilities that are provably impossible to attain in any classical network. Here, we take the first step from a physics experiment to a quantum internet system. We propose a functional allocation of a quantum network stack, and construct the first physical and link layer protocols that turn ad-hoc physics experiments producing heralded entanglement between quantum processors into a well-defined and robust service. This lays the groundwork for designing and implementing scalable control and application protocols in platform-independent software. To design our protocol, we identify use cases, as well as fundamental and technological design considerations of quantum network hardware, illustrated by considering the state-of-the-art quantum processor platform available to us (Nitrogen-Vacancy (NV) centers in diamond). Using a purpose built discrete-event simulator for quantum networks, we examine the robustness and performance of our protocol using extensive simulations on a supercomputing cluster. We perform a full implementation of our protocol in our simulator, where we successfully validate the physical simulation model against data gathered from the NV hardware. We first observe that our protocol is robust even in a regime of exaggerated losses of classical control messages with only little impact on the performance of the system. We proceed to study the performance of our protocols for 169 distinct simulation scenarios, including trade-offs between traditional performance metrics such as throughput, and the quality of entanglement. Finally, we initiate the study of quantum network scheduling strategies to optimize protocol performance for different use cases.QID/Wehner GroupQuTechQID/Elkouss GroupElectrical Engineering, Mathematics and Computer ScienceQID/Hanson LabEmbedded and Networked SystemsBusiness DevelopmentQN/Hanson LabQuantum Internet DivisionQuantum Information and Softwar

Distributed entanglement and teleportation on a quantum network

We report on the realization of a multi-node quantum network. Using the network, we have demonstrated three protocols; generation of a entangled state shared by all nodes, entanglement swapping and quantum teleportation between non-neighboring nodes.Green Open Access added to TU Delft Institutional Repository ‘You share, we take care!’ – Taverne project https://www.openaccess.nl/en/you-share-we-take-care Otherwise as indicated in the copyright section: the publisher is the copyright holder of this work and the author uses the Dutch legislation to make this work public.QID/Hanson LabQCD/Vandersypen LabALG/GeneralBUS/Quantum DelftQID/Wehner GroupQN/Borregaard groepQuantum Computer ScienceQN/Hanson La

Experimental demonstration of entanglement delivery using a quantum network stack

Scaling current quantum communication demonstrations to a large-scale quantum network will require not only advancements in quantum hardware capabilities, but also robust control of such devices to bridge the gap in user demand. Moreover, the abstraction of tasks and services offered by the quantum network should enable platform-independent applications to be executed without the knowledge of the underlying physical implementation. Here we experimentally demonstrate, using remote solid-state quantum network nodes, a link layer, and a physical layer protocol for entanglement-based quantum networks. The link layer abstracts the physical-layer entanglement attempts into a robust, platform-independent entanglement delivery service. The system is used to run full state tomography of the delivered entangled states, as well as preparation of a remote qubit state on a server by its client. Our results mark a clear transition from physics experiments to quantum communication systems, which will enable the development and testing of components of future quantum networks.QID/Hanson LabElectrical Engineering, Mathematics and Computer ScienceQID/Software GroupQID/Wehner GroupHospitality & Events Support OperationsEmbedded and Networked SystemsQN/Hanson LabQuantum Information and Softwar