28 results on '"Zahidy, Mujtaba"'
Search Results
2. Temporal Multiplexing of Heralded Photons Based on Thin Film Lithium Niobate Photonics
- Author
-
Ekici, Cagin, Yu, Yonghe, Adcock, Jeremy C., Muthali, Alif Laila, Zahidy, Mujtaba, Tan, Heyun, Lin, Zhongjin, Li, Hao, Oxenløwe, Leif K., Cai, Xinlun, and Ding, Yunhong
- Subjects
Quantum Physics - Abstract
Heralded photons from a silicon source are temporally multiplexed utilizing thin film lithium niobate photonics. The time-multiplexed source, operating at a rate of R = 62.2 MHz, enhances single photon probability by 3.25 $\pm$ 0.05.
- Published
- 2023
3. Single-Photon-Based Clock Analysis and Recovery in Quantum Key Distribution
- Author
-
Zahidy, Mujtaba, Ribezzo, Domenico, Müller, Ronny, Riebesehl, Jasper, Zavatta, Alessandro, Galili, Michael, Oxenløwe, Leif Katsuo, and Bacco, Davide
- Subjects
Quantum Physics - Abstract
Quantum key distribution is one of the first quantum technologies ready for the market. Current quantum telecommunication systems usually utilize a service channel for synchronizing the transmitter (Alice) and the receiver (Bob). However, the possibility of removing this service channel and exploiting a clock recovery method is intriguing for future implementation, both in fiber and free-space links. In this paper, we investigate criteria to recover the clock in a quantum communication scenario, and experimentally demonstrated the possibility of using a quantum-based clock recovery system in a time-bin quantum key distribution protocol. The performance of the clock recovery technique, in terms of quantum bit error rate and secret key rate, is equivalent to using the service channel for clock sharing., Comment: 10 pages, 7 figures
- Published
- 2023
4. Efficient Information Reconciliation for High-Dimensional Quantum Key Distribution
- Author
-
Mueller, Ronny, Ribezzo, Domenico, Zahidy, Mujtaba, Oxenløwe, Leif Katsuo, Bacco, Davide, and Forchhammer, Søren
- Subjects
Quantum Physics - Abstract
The Information Reconciliation phase in quantum key distribution has significant impact on the range and throughput of any QKD system. We explore this stage for high-dimensional QKD implementations and introduce two novel methods for reconciliation. The methods are based on nonbinary LDPC codes and the Cascade algorithm, and achieve efficiencies close the the Slepian-Wolf bound on q-ary symmetric channels., Comment: 17 pages, 5 figures. arXiv admin note: text overlap with arXiv:2305.08631
- Published
- 2023
5. Generalized Time-bin Quantum Random Number Generator with Uncharacterized Devices
- Author
-
Tebyanian, Hamid, Zahidy, Mujtaba, Müller, Ronny, Forchhammer, Søren, Bacco, Davide, and Oxenløwe, Leif. K.
- Subjects
Quantum Physics - Abstract
Random number generators (RNG) based on quantum mechanics are captivating due to their security and unpredictability compared to conventional generators, such as pseudo-random number generators and hardware-random number generators. This work analyzes evolutions in the extractable amount of randomness with increasing the Hilbert space dimension, state preparation subspace, or measurement subspace in a class of semi-device-independent quantum-RNG, where bounding the states' overlap is the core assumption, built on the prepare-and-measure scheme. We further discuss the effect of these factors on the complexity and draw a conclusion on the optimal scenario. We investigate the generic case of time-bin encoding scheme, define various input (state preparation) and outcome (measurement) subspaces, and discuss the optimal scenarios to obtain maximum entropy. Several input designs were experimentally tested and analyzed for their conceivable outcome arrangements. We evaluated their performance by considering the device's imperfections, particularly the after-pulsing effect and dark counts of the detectors. Finally, we demonstrate that this approach can boost the system entropy, resulting in more extractable randomness., Comment: 9 pages, 6 figures
- Published
- 2023
6. Generalized time-bin quantum random number generator with uncharacterized devices
- Author
-
Tebyanian, Hamid, Zahidy, Mujtaba, Müller, Ronny, Forchhammer, Søren, Bacco, Davide, and Oxenløwe, Leif. K.
- Published
- 2024
- Full Text
- View/download PDF
7. Practical high-dimensional quantum key distribution protocol over deployed multicore fiber
- Author
-
Zahidy, Mujtaba, Ribezzo, Domenico, De Lazzari, Claudia, Vagniluca, Ilaria, Biagi, Nicola, Müller, Ronny, Occhipinti, Tommaso, Oxenløwe, Leif K., Galili, Michael, Hayashi, Tetsuya, Cassioli, Dajana, Mecozzi, Antonio, Antonelli, Cristian, Zavatta, Alessandro, and Bacco, Davide
- Published
- 2024
- Full Text
- View/download PDF
8. Quantum key distribution using deterministic single-photon sources over a field-installed fibre link
- Author
-
Zahidy, Mujtaba, Mikkelsen, Mikkel T., Müller, Ronny, Da Lio, Beatrice, Krehbiel, Martin, Wang, Ying, Bart, Nikolai, Wieck, Andreas D., Ludwig, Arne, Galili, Michael, Forchhammer, Søren, Lodahl, Peter, Oxenløwe, Leif K., Bacco, Davide, and Midolo, Leonardo
- Published
- 2024
- Full Text
- View/download PDF
9. Quantum Key Distribution over 100 km underwater optical fiber assisted by a Fast-Gated Single-Photon Detector
- Author
-
Ribezzo, Domenico, Zahidy, Mujtaba, Lemmi, Gianmarco, Petitjean, Antoine, De Lazzari, Claudia, Vagniluca, Ilaria, Conca, Enrico, Tosi, Alberto, Occhipinti, Tommaso, Oxenløwe, Leif K., Xuereb, Andrè, Bacco, Davide, and Zavatta, Alessandro
- Subjects
Quantum Physics - Abstract
Nowadays Quantum Key Distribution represents the most mature quantum technology, and multiple countries as well as private institutions are building their quantum network. However, QKD devices are still far from representing a product within everyone's reach. Indeed, limitations in terms of compatibility with existing telecom infrastructure and limited performances in terms of secret key rate, using non-cryogenic detection systems, are still critical. In this work, we implemented a quantum key distribution link between Sicily (Italy) and Malta utilizing two different Single-Photon Avalanche Diode (SPAD) detectors. The performances of a standard commercial SPAD have been compared with the results achieved with a new prototype of fast-gated System in a Package (SiP) SPAD; the SiP detector has shown to be able to accomplish a fourteen times higher key rate compared with the commercial device over the channel showing 20 dB of losses.
- Published
- 2023
- Full Text
- View/download PDF
10. Quantum Key Distribution using Deterministic Single-Photon Sources over a Field-Installed Fibre Link
- Author
-
Zahidy, Mujtaba, Mikkelsen, Mikkel T., Müller, Ronny, Da Lio, Beatrice, Krehbiel, Martin, Wang, Ying, Bart, Nikolai, Wieck, Andreas D., Ludwig, Arne, Galili, Michael, Forchhammer, Søren, Lodahl, Peter, Oxenløwe, Leif K., Bacco, Davide, and Midolo, Leonardo
- Subjects
Quantum Physics - Abstract
Quantum-dot-based single-photon sources are key assets for quantum information technology, supplying on-demand scalable quantum resources for computing and communication. However, longlasting issues such as limited long-term stability and source brightness have traditionally impeded their adoption in real-world applications. Here, we realize a quantum key distribution field trial using true single photons across an 18-km-long dark fibre, located in the Copenhagen metropolitan area, using an optimized, state-of-the-art, quantum-dot single-photon source frequency-converted to the telecom wavelength. A secret key generation rate of >2 kbits/s realized over a 9.6 dB channel loss is achieved with a polarization-encoded BB84 scheme, showing remarkable stability for more than 24 hours of continuous operation. Our results highlight the maturity of deterministic single-photon source technology while paving the way for advanced single-photon-based communication protocols, including fully device-independent quantum key distribution, towards the goal of a quantum internet., Comment: 9 pages, 4 figures. Minor edits
- Published
- 2023
11. Deploying an inter-European quantum network
- Author
-
Ribezzo, Domenico, Zahidy, Mujtaba, Vagniluca, Ilaria, Biagi, Nicola, Francesconi, Saverio, Occhipinti, Tommaso, Oxenløwe, Leif K., Lončarić, Martin, Cvitić, Ivan, Stipčević, Mario, Pušavec, Žiga, Kaltenbaek, Rainer, Ramšak, Anton, Cesa, Francesco, Giorgetti, Giorgio, Scazza, Francesco, Bassi, Angelo, De Natale, Paolo, Cataliotti, Francesco Saverio, Inguscio, Massimo, Bacco, Davide, and Zavatta, Alessandro
- Subjects
Quantum Physics - Abstract
Around forty years have passed since the first pioneering works have introduced the possibility of using quantum physics to strongly enhance communications safety. Nowadays Quantum Cryptography, and in particular, Quantum Key Distribution (QKD) exited the physics laboratories to become commercial technologies that increasingly trigger the attention of States, military forces, banks, and private corporations. This work takes on the challenge of bringing QKD closer to a consumer technology: optical fibers deployed and used by telecommunication companies of different States have been used to realize a quantum network, the first-ever connecting three different countries. This pushes towards the necessary coexistence of QKD and classical communications on the same infrastructure, which currently represents a main limit of this technology. Our network connects Trieste to Rijeka and Ljubljana via a trusted node in Postojna; a key rate of over 3 kbps has been achieved in the shortest link, and a 7-hour long measurement has demonstrated the system stability and reliability. Finally, the network has been used for a public demonstration of QKD at the G20 Digital Ministers' Meeting in Trieste. The reported experimental results, together with the significant interest that one of the most important events of international politics has attracted, showcase the maturity of the QKD technology bundle, placing it in the spotlight for consumer applications in the near term., Comment: 8 pages, 3 figures
- Published
- 2022
- Full Text
- View/download PDF
12. Quantum randomness generation via orbital angular momentum modes crosstalk in a ring-core fiber
- Author
-
Zahidy, Mujtaba, Tebyanian, Hamid, Cozzolino, Daniele, Liu, Yaoxin, Ding, Yunhong, Morioka, Toshio, Oxenløwe, Leif K., and Bacco, Davide
- Subjects
Quantum Physics - Abstract
Genuine random numbers can be produced beyond a shadow of doubt through the intrinsic randomness provided by quantum mechanics theory. While many degrees of freedom have been investigated for randomness generation, not adequate attention has been paid to the orbital angular momentum of light. In this work, we present a quantum random number generator based on the intrinsic randomness inherited from the superposition of orbital angular momentum modes caused by the crosstalk inside a ring-core fiber. We studied two possible cases: a first one, device-dependent, where the system is trusted, and a second one, semi-device-independent, where the adversary can control the measurements. We experimentally realized the former, extracted randomness, and, after privacy amplification, we achieved a generation rate higher than 10 Mbit/s. In addition, we presented a possible realization of the semi-device-independent protocol, using a newly introduced integrated silicon photonic chip. Our work can be considered as a starting point for novel investigations of quantum random number generators based on the orbital angular momentum of light., Comment: 5 pages, 6 figures
- Published
- 2021
- Full Text
- View/download PDF
13. Photonic integrated chip enabling orbital angular momentum multiplexing for quantum communication
- Author
-
Zahidy, Mujtaba, Liu, Yaoxin, Cozzolino, Daniele, Ding, Yunhong, Morioka, Toshio, Oxenløwe, Leif K., and Bacco, Davide
- Subjects
Quantum Physics - Abstract
Light carrying orbital angular momentum constitutes an important resource for both classical and quantum information technologies. Its inherently unbounded nature can be exploited to generate high-dimensional quantum states or for channel multiplexing in classical and quantum communication in order to significantly boost the data capacity and the secret key rate, respectively. While the big potentials of light owning orbital angular momentum have been widely ascertained, its technological deployment is still limited by the difficulties deriving from the fabrication of integrated and scalable photonic devices able to generate and manipulate it. Here, we present a photonic integrated chip able to excite orbital angular momentum modes in an 800 m long ring-core fiber, allowing us to perform parallel quantum key distribution using 2 and 3 different modes simultaneously. The experiment sets the first steps towards quantum orbital angular momentum division multiplexing enabled by a compact and light-weight silicon chip, and further pushes the development of integrated scalable devices supporting orbital angular momentum modes., Comment: 5 pages main text, 5 figures
- Published
- 2021
14. Practical Semi-Device Independent Randomness Generation Based on Quantum State's Indistinguishability
- Author
-
Tebyanian, Hamid, Zahidy, Mujtaba, Avesani, Marco, Stanco, Andrea, Villoresi, Paolo, and Vallone, Giuseppe
- Subjects
Quantum Physics - Abstract
Semi-device independent (Semi-DI) quantum random number generators (QRNG) gained attention for security applications, offering an excellent trade-off between security and generation rate. This paper presents a proof-of-principle time-bin encoding semi-DI QRNG experiments based on a prepare-and-measure scheme. The protocol requires two simple assumptions and a measurable condition: an upper-bound on the prepared pulses' energy. We lower-bound the conditional min-entropy from the energy-bound and the input-output correlation, determining the amount of genuine randomness that can be certified. Moreover, we present a generalized optimization problem for bounding the min-entropy in the case of multiple-input and outcomes in the form of a semidefinite program (SDP). The protocol is tested with a simple experimental setup, capable of realizing two configurations for the ternary time-bin encoding scheme. The experimental setup is easy-to-implement and comprises commercially available off-the-shelf (COTS) components at the telecom wavelength, granting a secure and certifiable entropy source. The combination of ease-of-implementation, scalability, high-security level, and output-entropy make our system a promising candidate for commercial QRNGs., Comment: 9 pages, 8 figures
- Published
- 2021
- Full Text
- View/download PDF
15. Resource-effective Quantum Key Distribution: a field-trial in Padua city center
- Author
-
Avesani, Marco, Calderaro, Luca, Foletto, Giulio, Agnesi, Costantino, Picciariello, Francesco, Santagiustina, Francesco, Scriminich, Alessia, Stanco, Andrea, Vedovato, Francesco, Zahidy, Mujtaba, Vallone, Giuseppe, and Villoresi, Paolo
- Subjects
Quantum Physics - Abstract
Field-trials are of key importance for novel technologies seeking commercialization and wide-spread adoption. This is certainly also the case for Quantum Key Distribution (QKD), which allows distant parties to distill a secret key with unconditional security. Typically, QKD demonstrations over urban infrastructures require complex stabilization and synchronization systems to maintain a low Quantum Bit Error (QBER) and high secret key rates over time. Here we present a field-trial which exploits a low-complexity self-stabilized hardware and a novel synchronization technique, to perform QKD over optical fibers deployed in the city center of Padua, Italy. In particular, two techniques recently introduced by our research group are evaluated in a real-world environment: the iPOGNAC polarization encoder was used for the preparation of the quantum states, while the temporal synchronization was performed using the Qubit4Sync algorithm. The results here presented demonstrate the validity and robustness of our resource-effective QKD system, that can be easily and rapidly installed in an existing telecommunication infrastructure, thus representing an important step towards mature, efficient and low-cost QKD systems., Comment: 5 pages, 3 figures
- Published
- 2020
- Full Text
- View/download PDF
16. Simple Quantum Key Distribution with qubit-based synchronization and a self-compensating polarization encoder
- Author
-
Agnesi, Costantino, Avesani, Marco, Calderaro, Luca, Stanco, Andrea, Foletto, Giulio, Zahidy, Mujtaba, Scriminich, Alessia, Vedovato, Francesco, Vallone, Giuseppe, and Villoresi, Paolo
- Subjects
Quantum Physics - Abstract
Quantum Key Distribution (QKD) relies on quantum communication to allow distant parties to share a secure cryptographic key. Widespread adoption of QKD in current telecommunication networks will require the development of simple, low cost and stable systems. However, current QKD implementations usually include additional hardware that perform auxiliary tasks such as temporal synchronization and polarization basis tracking. Here we present a polarization-based QKD system operating at 1550 nm that performs synchronization and polarization compensation by exploiting only the hardware already needed for the quantum communication task. Polarization encoding is performed by a self-compensating Sagnac loop modulator which exhibits high temporal stability and the lowest intrinsic quantum bit error rate reported so far.The QKD system was tested over a fiber-optic link, demonstrating tolerance up to about 40 dB of channel losses. Thanks to its reduced hardware requirements and the quality of the source, this work represents an important step towards technologically mature QKD systems., Comment: 8 pages, 4 figures
- Published
- 2019
- Full Text
- View/download PDF
17. Photonic integrated chip enabling orbital angular momentum multiplexing for quantum communication
- Author
-
Zahidy Mujtaba, Liu Yaoxin, Cozzolino Daniele, Ding Yunhong, Morioka Toshio, Oxenløwe Leif K., and Bacco Davide
- Subjects
orbital angular momentum ,quantum communication ,quantum key distribution ,silicon photonics ,Physics ,QC1-999 - Abstract
Light carrying orbital angular momentum constitutes an important resource for both classical and quantum information technologies. Its inherently unbounded nature can be exploited to generate high-dimensional quantum states or for channel multiplexing in classical and quantum communication in order to significantly boost the data capacity and the secret key rate, respectively. While the big potentials of light owning orbital angular momentum have been widely ascertained, its technological deployment is still limited by the difficulties deriving from the fabrication of integrated and scalable photonic devices able to generate and manipulate it. Here, we present a photonic integrated chip able to excite orbital angular momentum modes in an 800 m long ring-core fiber, allowing us to perform parallel quantum key distribution using two and three different modes simultaneously. The experiment sets the first steps towards quantum orbital angular momentum division multiplexing enabled by a compact and light-weight silicon chip, and further pushes the development of integrated scalable devices supporting orbital angular momentum modes.
- Published
- 2021
- Full Text
- View/download PDF
18. Electron-phonon interaction in an $N$-atomic 1-D periodic chain
- Author
-
Zahidy, Mujtaba, Ghadirian, Fatemeh, and Namiranian, Afshin
- Subjects
Condensed Matter - Mesoscale and Nanoscale Physics - Abstract
The study of electron-phonon interaction as a prominent inelastic effect is of great importance. In the present work, we have studied the inelastic effects due to the first order electron-phonon interactions on electronic properties of mono-atomic periodic chain, using the exact diagonalization technique. Hence, only acoustic modes are considered. To avoid the approximate results arising from Keldysh formalism and on-site electron-phonon interaction assumption, we have used the Green's function technique together with Fr\"{o}hlich Hamiltonian for the interaction part. Finally, as an example, we apply our method to the case of $N=6$ which could be considered as a Benzene-like molecule., Comment: 5 pages, 4 figures
- Published
- 2016
19. Quantum key distribution over 100 km of underwater optical fiber assisted by a fast-gated single-photon detector
- Author
-
Ribezzo, Domenico, Zahidy, Mujtaba, Lemmi, Gianmarco, Petitjean, Antoine, De Lazzari, Claudia, Vagniluca, Ilaria, Conca, Enrico, Tosi, Alberto, Occhipinti, Tommaso, Oxenløwe, Leif K., Xuereb, André, Bacco, Davide, Zavatta, Alessandro, Ribezzo, Domenico, Zahidy, Mujtaba, Lemmi, Gianmarco, Petitjean, Antoine, De Lazzari, Claudia, Vagniluca, Ilaria, Conca, Enrico, Tosi, Alberto, Occhipinti, Tommaso, Oxenløwe, Leif K., Xuereb, André, Bacco, Davide, and Zavatta, Alessandro
- Abstract
Nowadays quantum key distribution (QKD) represents the most mature quantum technology, and multiple countries as well as private institutions are building their quantum network. However, QKD devices are still far from representing a product within everyone's reach. Indeed, limitations in terms of compatibility with existing telecom infrastructure and limited performances in terms of secret key rate, using noncryogenic detection systems, are still critical. In this work, we implemented a quantum key distribution link between Sicily (Italy) and Malta utilizing two different single-photon avalanche diode (SPAD) detectors. The performances of a standard commercial SPAD have been compared with the results achieved with an alternative prototype of fast-gated system in a package (SIP) SPAD; the SIP detector has shown to be able to accomplish a 14 times higher key rate compared with the commercial device over the channel showing 20 dB of losses.
- Published
- 2023
20. Practical analysis of decoy method in QKD over underwater optical fiber
- Author
-
Hemmer, Philip R., Migdall, Alan L., Bacco, Davide, Ribezzo, Domenico, Zahidy, Mujtaba, De Lazzari, Claudia, Vagniluca, Ilaria, Petitjean, Antoine, Lemmi, Gianmarco, Occhipinti, Tommaso, Cataliotti, Francesco Saverio, Oxenløwe, Leif K., Xuereb, André, Zavatta, Alessandro, Hemmer, Philip R., Migdall, Alan L., Bacco, Davide, Ribezzo, Domenico, Zahidy, Mujtaba, De Lazzari, Claudia, Vagniluca, Ilaria, Petitjean, Antoine, Lemmi, Gianmarco, Occhipinti, Tommaso, Cataliotti, Francesco Saverio, Oxenløwe, Leif K., Xuereb, André, and Zavatta, Alessandro
- Abstract
Quantum key distribution (QKD) is the first commercial application of the second quantum revolution. Although QKD systems have already been developed and implemented all around the world, some open challenges are limiting the overall deployment of this technology (limited key rate, limited link distance, etc.). By improving the current QKD protocols, it is possible to increase the final secret key generation rate. In this work, we compare 1-decoy with 2-decoy methods in BB84 protocol over an underwater optical fiber link connecting Malta to Italy, showing that 2-decoy can achieve more than twice the key rate of 1-decoy method.
- Published
- 2023
21. Deploying an Inter-European Quantum Network
- Author
-
Ribezzo, Domenico, Zahidy, Mujtaba, Vagniluca, Ilaria, Biagi, Nicola, Francesconi, Saverio, Occhipinti, Tommaso, Oxenløwe, Leif K., Lončarić, Martin, Cvitić, Ivan, Stipčević, Mario, Pušavec, Žiga, Kaltenbaek, Rainer, Ramšak, Anton, Cesa, Francesco, Giorgetti, Giorgio, Scazza, Francesco, Bassi, Angelo, De Natale, Paolo, Cataliotti, Francesco Saverio, Inguscio, Massimo, Bacco, Davide, Zavatta, Alessandro, Ribezzo, Domenico, Zahidy, Mujtaba, Vagniluca, Ilaria, Biagi, Nicola, Francesconi, Saverio, Occhipinti, Tommaso, Oxenløwe, Leif K., Lončarić, Martin, Cvitić, Ivan, Stipčević, Mario, Pušavec, Žiga, Kaltenbaek, Rainer, Ramšak, Anton, Cesa, Francesco, Giorgetti, Giorgio, Scazza, Francesco, Bassi, Angelo, De Natale, Paolo, Cataliotti, Francesco Saverio, Inguscio, Massimo, Bacco, Davide, and Zavatta, Alessandro
- Abstract
Around 40 years have passed since the first pioneering works introduced the possibility of using quantum physics to enhance communications safety. Nowadays, quantum key distribution (QKD) exited the physics laboratories to become a mature technology, triggering the attention of States, military forces, banks, and private corporations. This work takes on the challenge of bringing QKD closer to a consumer technology: deployed optical fibers by telecommunication companies of different States have been used to realize a quantum network, the first-ever connecting three different countries. This work also emphasizes the necessity of networks where QKD can come up besides classical communications, whose coexistence currently represents the main limitation of this technology. This network connects Trieste to Rijeka and Ljubljana via a trusted node in Postojna. A key rate of over 3 kbps in the shortest link and a 7-hour-long measurement demonstrate the system's stability and reliability. The network has been used to present the QKD at the G20 Digital Ministers' Meeting in Trieste. The experimental results, together with the interest that one of the most important events of international politics has attracted, showcase the maturity of the QKD technology bundle, placing it in the spotlight for consumer applications in the near term.
- Published
- 2023
22. Quantum Key Distribution using True On-demand Single Photons over a Field-Installed Fiber Link
- Author
-
Zahidy, Mujtaba, Krehbiel, Martin, Lodahl, Peter, Mikkelsen, Mikkel T., Wang, Ying, Oxenlowe, Leif K., Muller, Ronny, Galili, Michael, Bacco, Davide, Da Lio, Beatrice, Forchhammer, Soren, Midolo, Leonardo, Zahidy, Mujtaba, Krehbiel, Martin, Lodahl, Peter, Mikkelsen, Mikkel T., Wang, Ying, Oxenlowe, Leif K., Muller, Ronny, Galili, Michael, Bacco, Davide, Da Lio, Beatrice, Forchhammer, Soren, and Midolo, Leonardo
- Abstract
We report on a quantum key distribution field trial in the Copenhagen metropolitan area using true single photons from a quantum-dot-based near-deterministic source. A stable secret key generation rate of 2 kbit/s with 9.6-dB channel loss is achieved with a polarization-based BB84 scheme.
- Published
- 2022
23. Quantum randomness generation via orbital angular momentum modes crosstalk in a ring-core fiber
- Author
-
Zahidy, Mujtaba, Tebyanian, Hamid, Cozzolino, Daniele, Liu, Yaoxin, Ding, Yunhong, Morioka, Toshio, Oxenløwe, Leif K., Bacco, Davide, Zahidy, Mujtaba, Tebyanian, Hamid, Cozzolino, Daniele, Liu, Yaoxin, Ding, Yunhong, Morioka, Toshio, Oxenløwe, Leif K., and Bacco, Davide
- Abstract
Genuine random numbers can be produced beyond a shadow of doubt through the intrinsic randomness provided by quantum mechanics theory. While many degrees of freedom have been investigated for randomness generation, not adequate attention has been paid to the orbital angular momentum of light. In this work, we present a quantum random number generator based on the intrinsic randomness inherited from the superposition of orbital angular momentum modes caused by the crosstalk inside a ring-core fiber. We studied two possible cases: a first one, device-dependent, where the system is trusted, and a second one, semi-device-independent, where the adversary can control the measurements. We experimentally realized the former, extracted randomness, and, after privacy amplification, we achieved a generation rate higher than 10 Mbit/s. In addition, we presented a possible realization of the semi-device-independent protocol, using a newly introduced integrated silicon photonic chip. Our work can be considered as a starting point for novel investigations of quantum random number generators based on the orbital angular momentum of light.
- Published
- 2022
24. Supplementary document for Simple quantum key distribution with qubit-based synchronization and a self-compensating polarization encoder - 4418478.pdf
- Author
-
Agnesi, Costantino, Avesani, Marco, Calderaro, Luca, Stanco, Andrea, Foletto, Giulio, Zahidy Mujtaba, Scriminich, Alessia, Vedovato, Francesco, Vallone, Giuseppe, and Villoresi, Paolo
- Abstract
Supplemental Document describing additional information on the Intensity Modulator and on Fine-Key security analysis
- Published
- 2020
- Full Text
- View/download PDF
25. Zahidy, Mujtaba
- Author
-
Zahidy, Mujtaba and Zahidy, Mujtaba
- Published
- 2020
26. Simple quantum key distribution with qubit-based synchronization and a self-compensating polarization encoder
- Author
-
Agnesi, Costantino, primary, Avesani, Marco, additional, Calderaro, Luca, additional, Stanco, Andrea, additional, Foletto, Giulio, additional, Zahidy, Mujtaba, additional, Scriminich, Alessia, additional, Vedovato, Francesco, additional, Vallone, Giuseppe, additional, and Villoresi, Paolo, additional
- Published
- 2020
- Full Text
- View/download PDF
27. Photonic integrated chip enabling orbital angular momentum multiplexing for quantum communication.
- Author
-
Zahidy, Mujtaba, Liu, Yaoxin, Cozzolino, Daniele, Ding, Yunhong, Morioka, Toshio, Oxenløwe, Leif K., and Bacco, Davide
- Subjects
QUANTUM communication ,ANGULAR momentum (Mechanics) ,QUANTUM states - Abstract
Light carrying orbital angular momentum constitutes an important resource for both classical and quantum information technologies. Its inherently unbounded nature can be exploited to generate high-dimensional quantum states or for channel multiplexing in classical and quantum communication in order to significantly boost the data capacity and the secret key rate, respectively. While the big potentials of light owning orbital angular momentum have been widely ascertained, its technological deployment is still limited by the difficulties deriving from the fabrication of integrated and scalable photonic devices able to generate and manipulate it. Here, we present a photonic integrated chip able to excite orbital angular momentum modes in an 800 m long ring-core fiber, allowing us to perform parallel quantum key distribution using two and three different modes simultaneously. The experiment sets the first steps towards quantum orbital angular momentum division multiplexing enabled by a compact and light-weight silicon chip, and further pushes the development of integrated scalable devices supporting orbital angular momentum modes. [ABSTRACT FROM AUTHOR]
- Published
- 2022
- Full Text
- View/download PDF
28. Deploying an Inter-European quantum network
- Author
-
Domenico Ribezzo, Mujtaba Zahidy, Ilaria Vagniluca, Nicola Biagi, Saverio Francesconi, Tommaso Occhipinti, Leif K. Oxenløwe, Martin Lončarić, Ivan Cvitić, Mario Stipčević, Žiga Pušavec, Rainer Kaltenbaek, Anton Ramšak, Francesco Cesa, Giorgio Giorgetti, Francesco Scazza, Angelo Bassi, Paolo De Natale, Francesco Saverio Cataliotti, Massimo Inguscio, Davide Bacco, Alessandro Zavatta, Ribezzo, Domenico, Zahidy, Mujtaba, Vagniluca, Ilaria, Biagi, Nicola, Francesconi, Saverio, Occhipinti, Tommaso, Oxenløwe, Leif K., Lončarić, Martin, Cvitić, Ivan, Stipčević, Mario, Pušavec, Žiga, Kaltenbaek, Rainer, Ramšak, Anton, Cesa, Francesco, Giorgetti, Giorgio, Scazza, Francesco, Bassi, Angelo, De Natale, Paolo, Cataliotti, Francesco Saverio, Inguscio, Massimo, Bacco, Davide, and Zavatta, Alessandro
- Subjects
Quantum Physics ,Nuclear and High Energy Physics ,Physics ,QKD ,European quantum communication infrastructure ,fibre optic network ,quantum communication ,quantum communication field trial ,quantum internet ,quantum key distribution ,quantum network ,FOS: Physical sciences ,Statistical and Nonlinear Physics ,Condensed Matter Physics ,Electronic, Optical and Magnetic Materials ,Quantum criptography ,Quantum communication ,Computational Theory and Mathematics ,Electrical and Electronic Engineering ,Quantum Physics (quant-ph) ,Mathematical Physics - Abstract
Around forty years have passed since the first pioneering works have introduced the possibility of using quantum physics to strongly enhance communications safety. Nowadays Quantum Cryptography, and in particular, Quantum Key Distribution (QKD) exited the physics laboratories to become commercial technologies that increasingly trigger the attention of States, military forces, banks, and private corporations. This work takes on the challenge of bringing QKD closer to a consumer technology: optical fibers deployed and used by telecommunication companies of different States have been used to realize a quantum network, the first-ever connecting three different countries. This pushes towards the necessary coexistence of QKD and classical communications on the same infrastructure, which currently represents a main limit of this technology. Our network connects Trieste to Rijeka and Ljubljana via a trusted node in Postojna; a key rate of over 3 kbps has been achieved in the shortest link, and a 7-hour long measurement has demonstrated the system stability and reliability. Finally, the network has been used for a public demonstration of QKD at the G20 Digital Ministers' Meeting in Trieste. The reported experimental results, together with the significant interest that one of the most important events of international politics has attracted, showcase the maturity of the QKD technology bundle, placing it in the spotlight for consumer applications in the near term., Comment: 8 pages, 3 figures
- Published
- 2022
Catalog
Discovery Service for Jio Institute Digital Library
For full access to our library's resources, please sign in.