Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Log inSign up
Challenges
Datasets
Workspaces
Papers
Discussions
Leaderboard
Blog
Job Board
Q3AS

© 2026 Aqora Quantum S.A.S.

TermsPrivacyLegal Notice

arXiv:2010.07127 · New Journal of Physics

Entanglement transfer, accumulation and retrieval via quantum-walk-based qubit–qudit dynamics

Taira Giordani, Luca Innocenti, Alessia Suprano, Emanuele Polino, Mauro Paternostro, Nicolò Spagnolo, Fabio Sciarrino, Alessandro Ferraro

Published Jan 15, 2021• 1 citation
arXivHTMLPDF

Abstract

Abstract The generation and control of quantum correlations in high-dimensional systems is a major challenge in the present landscape of quantum technologies. Achieving such non-classical high-dimensional resources will potentially unlock enhanced capabilities for quantum cryptography, communication and computation. We propose a protocol that is able to attain entangled states of d-dimensional systems through a quantum-walk (QW)-based transfer & accumulate mechanism involving coin and walker degrees of freedom. The choice of investigating QW is motivated by their generality and versatility, complemented by their successful implementation in several physical systems. Hence, given the cross-cutting role of QW across quantum information, our protocol potentially represents a versatile general tool to control high-dimensional entanglement generation in various experimental platforms. In particular, we illustrate a possible photonic implementation where the information is encoded in the orbital angular momentum and polarization degrees of freedom of single photons.

DOI
10.1088/1367-2630/abdbe1

Related papers

Entanglement transfer, accumulation and retrieval via quantum-walk-based qubit-qudit dynamics

Taira Giordani, Luca Innocenti, Suprano A. +5 more

The generation and control of quantum correlations in high-dimensional systems is a major challenge in the present landscape of quantum technologies. Achieving such non-classical high-dimensional resources will potentially unlock enhanced capabilities for quantum cryptography, communication and computation. We propose a protocol that is able to attain entangled states of d-dimensional systems through a quantum-walk (QW)-based transfer & accumulate mechanism involving coin and walker degrees of freedom. The choice of investigating QW is motivated by their generality and versatility, complemented by their successful implementation in several physical systems. Hence, given the cross-cutting role of QW across quantum information, our protocol potentially represents a versatile general tool to control high-dimensional entanglement generation in various experimental platforms. In particular, we illustrate a possible photonic implementation where the information is encoded in the orbital angular momentum and polarization degrees of freedom of single photons.

•Jan 1, 2021•17 citations

Generation of high-dimensional qudit quantum states via two-dimensional quantum walks

Chiara Esposito, Francesco Di Colandrea, Francesco Hoch +5 more

Several quantum protocols, with applications ranging from fundamental studies to cryptographic scenarios, can be enhanced through the generation and manipulation of quantum states that belong to high-dimensional Hilbert spaces. For this reason, it is worth devoting efforts to find more efficient methods for complex qudit-state generation. One-dimensional quantum walks have proved to be efficient and versatile platforms for the engineering of such complex states. Hitherto, however, using their two-dimensional counterpart for this task has remained unexplored. In this paper, we consider two-dimensional quantum walk evolution as a tool for the generation of high-dimensional qudit states. We theoretically prove that a suitable change of the coin operators at each step permits the generation of a subset of qudit states by using less resources with respect to the one-dimensional counterpart. Then, we successfully generate qudit states by exploiting two-dimensional quantum walks on an experimental photonic platform. The walker position is encoded on discrete sets of optical modes carrying quantized amounts of transverse momentum and the mode couplings are actively controlled via liquid-crystal devices. The obtained results provide insight into qudit generation for applications in quantum communication and quantum cryptography.

Physical Review Research•Oct 10, 2023•8 citations

Experimental Engineering of Arbitrary Qudit States with Discrete-Time Quantum Walks

Taira Giordani, Emanuele Polino, Sabrina Emiliani +8 more

The capability to generate and manipulate quantum states in high-dimensional Hilbert spaces is a crucial step for the development of quantum technologies, from quantum communication to quantum computation. One-dimensional quantum walk dynamics represents a valid tool in the task of engineering arbitrary quantum states. Here we affirm such potential in a linear-optics platform that realizes discrete-time quantum walks in the orbital angular momentum degree of freedom of photons. Different classes of relevant qudit states in a six-dimensional space are prepared and measured, confirming the feasibility of the protocol. Our results represent a further investigation of quantum walk dynamics in photonics platforms, paving the way for the use of such a quantum state-engineering toolbox for a large range of applications.

arXiv:1808.08875•Physical Review Letters•Jan 18, 2019•107 citations

Two Photon Tripartite Entanglement Transfer via Time-Multiplexed Quantum Walks

Jonas Lammers, Federico Pegoraro, Philip Held +3 more

Photonic multidimensional quantum networks (MDQN), where individual subsystems are encoded using multiple degrees of freedom and photons, are an emerging platform for quantum algorithms because they offer high scalability. The distribution of non-classical and non-local correlations between the individual subsystems in an MDQN is of fundamental interest for many quantum protocols. Interestingly in an MDQN, the inseparability of two subsystems underlying entanglement can occur both between multiple distinct photons as well as between individual degrees of freedom associated with a single photon. In this work, we investigate the entanglement transfer enabled by the interplay of both entanglement between two distinct photons as well as inseparability between multiple degrees of freedom. For this purpose, we subject one photon of a polarization entangled two-photon pair to a discrete-time quantum walk introducing the position subsystem of the quantum walk as a third subsystem with qudit encoding. Here we study the resulting transfer of entanglement from the polarization degree of freedom, representing qubit encoding, towards the position degree of freedom, representing quidt encoding, via partial state tomography and correlation measurements.

quant-pharXiv:2512.18523•Dec 23, 2025•0 citations

Experimental engineering of OAM quantum states with photonics quantum walks (Conference Presentation)

Fabio Sciarrino

The preparation of high-dimensional quan- tum states is of great significance in quantum information sci- ence and technology. Compared to qubits, qudit states – de- scribing quantum systems in d-dimensional spaces – enable stronger foundational tests of quantum mechanics [1–3] and better-performing applications in secure quantum communi- cations [4–9], quantum emulation [10, 11], quantum error cor- rection [12–14], fault-tolerant quantum computation [15–19], and quantum machine learning [20–22]. Needless to say, protocols performed on systems living in Hilbert spaces of large dimension require an increasing degree of control, in light of the large number of parameters required to describe states and operations. Nonetheless, the endeav- our of preparing arbitrary qudit states has been successfully achieved in various physical platforms [11, 23–32]. However, most of these works rely on ad hoc strategies, whose specific dependence on the underpinning dynamics makes their trans- lation across different physical platforms very difficult. A very promising way to achieve the desired full inde- pendence of the physical platform, and thus a higher degree of universality, is the use of the rich dynamics offered by Quantum Walks (QWs) [33–35]. QWs, which can be thought of as the quantum counterparts of classical random walks, describe in their discrete version a high-dimensional qudit, named walker, embedded with an internal two-dimensional degree of freedom, conventionally dubbed coin. At every time step, the walker’s state moves coherently to the neighbouring sites in the lattice, conditionally to its coin state [36]. QWs have been successfully implemented [37] in systems as di- verse as trapped atoms [38] and ions [39, 40], photonic cir- cuits [41–50], and optical lattices [51]. Hence, an approach for state engineering based on their dynamics offers hope of being applicable effectively in a variety of different systems, independently of the details of the physical implementation. While the QW dynamics was previously shown to allow the engineering of specific walker’s states [52, 53], in Ref. [54] a scheme was proposed to use discrete-time QWs on a line to prepare arbitrary qudit states. This is achieved by enhanc- ing the degree of control over the walk’s dynamics through the arrangement of suitable step-dependent coin operations, which affect the coin-walker quantum correlations by de facto steering the state of the walker towards the desired final state, and finally projecting in the coin space. This last operation removes the correlations between walker and coin, thus pro- ducing a pure walker state with the desired features. In light of the large parameter space that characterizes the problem at hand, a systematic approach to the identification of the right set of coin operations and final projection is necessary. Such an analysis was presented in Ref. [54], in which a set of an- alytic conditions, together with suitable numerical optimiza- tions, was shown to guarantee the reaching of arbitrary target states with high probability. In this paper, we make use of the scheme of Ref. [54] to give the first demonstration of a state-engineering protocol based on the controlled dynamics generated by QWs. We use the orbital angular momentum (OAM) degree of freedom of single-photon states as a convenient embodiment of the walker [48, 55, 56]. OAM-based experiments offer the pos- sibility to cover Hilbert spaces of large dimensions in light of the favourable (linear) scaling of the number of optical ele- ments with the size of the walk. Moreover, the scheme al- lows for the full control of the coin operation that is key to the implementation of the walk. In order to demonstrate the ver- satility of our scheme, we focus on the interesting classes of cat-like states and spin-coherent states [57, 58]. Those classes play a critical role in the exploration of the boundaries be- tween quantum and classical physics and whose implementa- tion is, in general, still a challenging task. Furthermore, we show experimentally the capability of engineering arbitrary states. The quality of the states synthesized in our endeavours, and the relative simplicity of the experimental protocol that we have put in place, demonstrate the effectiveness of a hybrid platform for quantum state engineering. Such platform holds together a programmable quantum system, the photonic QW in the angular momentum, and classical optimization al- gorithms for finding the best evolution to reach a certain quantum target. [1] T. Ve ́rtesi, S. Pironio, and N. Brunner, Physical Review Letters 104, 060401 (2010). [2] N. Brunner, D. Cavalcanti, S. Pironio, V. Scarani, and S. Wehner, Reviews of Modern Physics 86, 419 (2014). [3] R. Lapkiewicz, P. Li, C. Schaeff, N. K. Langford, S. Ramelow, M. Wies ́niak, and A. Zeilinger, Nature 474, 490 (2011). [4] H. Bechmann-Pasquinucci and A. Peres, Physical Review Let- ters 85, 3313 (2000). [5] M. Fitzi, N. Gisin, and U. Maurer, Physical Review Letters 87, 217901 (2001). [6] N. J. Cerf, M. Bourennane, A. Karlsson, and N. Gisin, Physical Review Letters 88, 127902 (2002). [7] D. Bruß and C. Macchiavello, Physical Review Letters 88, 127901 (2002). [8] A. Acin, N. Gisin, and V. Scarani, (2003), quant-ph/0303009. [9] N. K. Langford, R. B. Dalton, M. D. Harvey, J. L. O’Brien, G. J. Pryde, A. Gilchrist, S. D. Bartlett, and A. G. White, Physical Review Letters 93, 053601 (2004). [10] I. Buluta and F. Nori, Science 326, 108 (2009). [11] M. Neeley, M. Ansmann, R. C. Bialczak, M. Hofheinz, E. Lucero, A. D. O’Connell, D. Sank, H. Wang, J. Wenner, A. N. Cleland, M. R. Geller, and J. M. Martinis, Science 325, 722 (2009). [12] I. L. Chuang, D. W. Leung, and Y. Yamamoto, Physical Review A 56, 1114 (1997). [13] G. Duclos-Cianci and D. Poulin, Physical Review A 87, 062338 (2013). [14] M. H. Michael, M. Silveri, R. T. Brierley, V. V. Albert, J. Salmilehto, L. Jiang, and S. M. Girvin, Physical Review X 6, 031006 (2016). [15] S. D. Bartlett, H. d. Guise, and B. C. Sanders, Physical Review A 65, 052316 (2002). [16] T. C. Ralph, K. J. Resch, and A. Gilchrist, Physical Review A 75, 022313 (2007). [17] B. P. Lanyon, M. Barbieri, M. P. Almeida, T. Jennewein, T. C. Ralph, K. J. Resch, G. J. Pryde, J. L. O’Brien, A. Gilchrist, and A. G. White, Nature Physics 5, 134 (2009). [18] E. T. Campbell, H. Anwar, and D. E. Browne, Physical Review X 2, 041021 (2012). [19] E. T. Campbell, Physical Review Letters 113, 230501 (2014). [20] M. Schuld, I. Sinayskiy, and F. Petruccione, Contemporary Physics 56, 172 (2015). [21] V. Dunjko and H. J. Briegel, arXiv:1709.02779. [22] J. Biamonte, P. Wittek, N. Pancotti, P. Rebentrost, N. Wiebe, and S. Lloyd, Nature 549, 195 (2017). [23] D. Leibfried, D. M. Meekhof, B. E. King, C. Monroe, W. M. Itano, and D. J. Wineland, Physical Review Letters 77, 4281 (1996). [24] M. Hofheinz, H. Wang, M. Ansmann, R. C. Bialczak, E. Lucero, M. Neeley, A. D. O’Connell, D. Sank, J. Wenner, J. M. Martinis, and A. N. Cleland, Nature 459, 546 (2009). [25] B. Anderson, H. Sosa-Martinez, C. Riofr ́ıo, I. H. Deutsch, and P. S. Jessen, Physical Review Letters 114, 240401 (2015). [26] S. P. Walborn, D. S. Lemelle, M. P. Almeida, and P. H. S. Ribeiro, Physical Review Letters 96, 090501 (2006). [27] G. Lima, L. Neves, R. Guzma ́n, E. S. Go ́mez, W. A. T. Nogueira, A. Delgado, A. Vargas, and C. Saavedra, Optics Express 19, 3542 (2011). [28] A. Rossi, G. Vallone, A. Chiuri, F. De Martini, and P. Mataloni, Physical Review Letters 102, 153902 (2009). [29] A. C. Dada, J. Leach, G. S. Buller, M. J. Padgett, and E. Andersson, Nature Physics 7, 677 (2011). [30] R. W. Heeres, P. Reinhold, N. Ofek, L. Frunzio, L. Jiang, M. H. Devoret, and R. J. Schoelkopf, Nature Communications 8, 94 (2017). [31] S. Rosenblum, Y. Y. Gao, P. Reinhold, C. Wang, C. J. Axline, L. Frunzio, S. M. Girvin, L. Jiang, M. Mirrahimi, M. H. Devoret, and R. J. Schoelkopf, Nature Comm. 9, 652 (2018). [32] Y. Chu, P. Kharel, T. Yoon, L. Frunzio, P. T. Rakich, and R. J. Schoelkopf, (2018), arXiv:1804.07426. [33] Y. Aharonov, L. Davidovich, and N. Zagury, Physical Review A 48, 1687 (1993). [34] J. Kempe, Contemporary Physics 44, 307 (2003). [35] S. E. Venegas-Andraca, Quantum Information Processing 11, 1015 (2012). [36] A. Ambainis, E. Bach, A. Nayak, A. Vishwanath, and J. Watrous, in STOC ’01 Proceedings of the thirty-third annual ACM symposium on Theory of computing (2001) pp. 37–49. [37] K. Manouchehri and J. Wang, Physical Implementation of Quantum Walks (Springer Berlin Heidelberg, Berlin, Heidelberg, 2014). [38] R. Coˆte ́, A. Russell, E. E. Eyler, and P. L. Gould, New Journal of Physics 8, 156 (2006). [39] H. Schmitz, R. Matjeschk, C. Schneider, J. Glueckert, M. Enderlein, T. Huber, and T. Schaetz, Physical Review Letters 103, 090504 (2009). [40] F. Za ̈hringer, G. Kirchmair, R. Gerritsma, E. Solano, R. Blatt, and C. F. Roos, Physical Review Letters 104, 100503 (2010). [41] H. B. Perets, Y. Lahini, F. Pozzi, M. Sorel, R. Morandotti, and Y. Silberberg, Physical Review Letters 100, 170506 (2008). [42] A. Peruzzo, M. Lobino, J. C. F. Matthews, N. Matsuda, A. Politi, K. Poulios, X.-Q. Zhou, Y. Lahini, N. Ismail, K. Wo ̈rhoff, Y. Bromberg, Y. Silberberg, M. G. Thompson, and J. L. O’Brien, Science 329, 1500 (2010). [43] M. A. Broome, A. Fedrizzi, B. P. Lanyon, I. Kassal, A. Aspuru- Guzik, and A. G. White, Phys. Rev. Lett. 104, 153602 (2010). [44] A. Schreiber, K. N. Cassemiro, V. Potocˇek, A. Ga ́bris, P. J. Mosley, E. Andersson, I. Jex, and C. Silberhorn, Physical Re- view Letters 104, 050502 (2010). [45] P. P. Rohde, A. Schreiber, M. Sˇtefanˇa ́k, I. Jex, and C. Silber- horn, New Journal of Physics 13, 013001 (2011). [46] L. Sansoni, F. Sciarrino, G. Vallone, P. Mataloni, A. Crespi, R. Ramponi, and R. Osellame, Physical Review Letters 108, 010502 (2012). [47] J. Boutari, A. Feizpour, S. Barz, C. Di Franco, M. S. Kim, W. S. Kolthammer, and I. A. Walmsley, Journal of Optics 18, 094007 (2016). [48] F. Cardano, F. Massa, H. Qassim, E. Karimi, S. Slussarenko, D. Paparo, C. de Lisio, F. Sciarrino, E. Santamato, R. W. Boyd, and L. Marrucci, Science Advances 1, e1500087 (2015). [49] F. Cardano, M. Maffei, F. Massa, B. Piccirillo, C. de Lisio, G. D. Filippis, V. Cataudella, E. Santamato, and L. Marrucci, Nature Communications 7, 11439 (2016). [50] F. Caruso, A. Crespi, A. G. Ciriolo, F. Sciarrino, and R. Osel- lame, Nature Communications 7, 11682 (2016). [51] F. Meinert, M. J. Mark, E. Kirilov, K. Lauber, P. Weinmann, M. Grobner, A. J. Daley, H.-C. Nagerl, N. Ismail, K. Wo ̈rhoff, Y. Bromberg, Y. Silberberg, M. G. Thompson, and J. L. OBrien, Science 344, 1259 (2014). [52] C. M. Chandrashekar, R. Srikanth, and R. Laflamme, Physical Review A 77, 032326 (2008). [53] H. Majury, J. Boutari, E. O’Sullivan, A. Ferraro, and M. Pater- nostro, EPJ Quant. Tech. 5, 1 (2018). [54] L. Innocenti, H. Majury, T. Giordani, N. Spagnolo, F. Sciar- rino, M. Paternostro, and A. Ferraro, Phys. Rev. A 96, 062326 (2017). [55] P.Zhang,B.H.Liu,R.F.Liu,H.R.Li,F.L.Li, andG.C. Guo, Physical Review Letters 81 (2010). [56] S. K. Goyal, F. S. Roux, A. Forbes, and T. Konrad, Physical Review Letters 110, 263602 (2013). [57] M. Brune, S. Haroche, J. M. Raimond, L. Davidovich, and N. Zagury, Phys. Rev. A 45, 5193 (1992). [58] C. Monroe, D. M. Meekhof, B. E. King, and D. J. Wineland, Science 272, 1131 (24 May 1996).

Complex Light and Optical Forces•Mar 8, 2019•0 citations

Engineering High-dimensional Entangled States via Discrete-time Quantum Walks

Taira Giordani, Alessia Suprano, Emanuele Polino +2 more

Discrete-time quantum walks (QWs) are versatile platforms in quantum information. In this work we engineer QWs encoded in the angular momentum of single-photon states, to transfer and accumulate entanglement between information carriers of different dimensions.

Conference on Lasers and Electro-Optics•Jan 1, 2021•0 citations
Abstract The generation and control of quantum correlations in high-dimensional systems is a major challenge in the present landscape of quantum technologies. Achieving such non-classical high-dimensional resources will potentially unlock enhanced capabilities for quantum cryptography, communication and computation. We propose a protocol that is able to attain entangled states of d-dimensional systems through a quantum-walk (QW)-based transfer & accumulate mechanism involving coin and walker degrees of freedom. The choice of investigating QW is motivated by their generality and versatility, complemented by their successful implementation in several physical systems. Hence, given the cross-cutting role of QW across quantum information, our protocol potentially represents a versatile general tool to control high-dimensional entanglement generation in various experimental platforms. In particular, we illustrate a possible photonic implementation where the information is encoded in the orbital angular momentum and polarization degrees of freedom of single photons.
The generation and control of quantum correlations in high-dimensional systems is a major challenge in the present landscape of quantum technologies. Achieving such non-classical high-dimensional resources will potentially unlock enhanced capabilities for quantum cryptography, communication and computation. We propose a protocol that is able to attain entangled states of d-dimensional systems through a quantum-walk (QW)-based transfer & accumulate mechanism involving coin and walker degrees of freedom. The choice of investigating QW is motivated by their generality and versatility, complemented by their successful implementation in several physical systems. Hence, given the cross-cutting role of QW across quantum information, our protocol potentially represents a versatile general tool to control high-dimensional entanglement generation in various experimental platforms. In particular, we illustrate a possible photonic implementation where the information is encoded in the orbital angular momentum and polarization degrees of freedom of single photons.
Several quantum protocols, with applications ranging from fundamental studies to cryptographic scenarios, can be enhanced through the generation and manipulation of quantum states that belong to high-dimensional Hilbert spaces. For this reason, it is worth devoting efforts to find more efficient methods for complex qudit-state generation. One-dimensional quantum walks have proved to be efficient and versatile platforms for the engineering of such complex states. Hitherto, however, using their two-dimensional counterpart for this task has remained unexplored. In this paper, we consider two-dimensional quantum walk evolution as a tool for the generation of high-dimensional qudit states. We theoretically prove that a suitable change of the coin operators at each step permits the generation of a subset of qudit states by using less resources with respect to the one-dimensional counterpart. Then, we successfully generate qudit states by exploiting two-dimensional quantum walks on an experimental photonic platform. The walker position is encoded on discrete sets of optical modes carrying quantized amounts of transverse momentum and the mode couplings are actively controlled via liquid-crystal devices. The obtained results provide insight into qudit generation for applications in quantum communication and quantum cryptography.
The capability to generate and manipulate quantum states in high-dimensional Hilbert spaces is a crucial step for the development of quantum technologies, from quantum communication to quantum computation. One-dimensional quantum walk dynamics represents a valid tool in the task of engineering arbitrary quantum states. Here we affirm such potential in a linear-optics platform that realizes discrete-time quantum walks in the orbital angular momentum degree of freedom of photons. Different classes of relevant qudit states in a six-dimensional space are prepared and measured, confirming the feasibility of the protocol. Our results represent a further investigation of quantum walk dynamics in photonics platforms, paving the way for the use of such a quantum state-engineering toolbox for a large range of applications.
Photonic multidimensional quantum networks (MDQN), where individual subsystems are encoded using multiple degrees of freedom and photons, are an emerging platform for quantum algorithms because they offer high scalability. The distribution of non-classical and non-local correlations between the individual subsystems in an MDQN is of fundamental interest for many quantum protocols. Interestingly in an MDQN, the inseparability of two subsystems underlying entanglement can occur both between multiple distinct photons as well as between individual degrees of freedom associated with a single photon. In this work, we investigate the entanglement transfer enabled by the interplay of both entanglement between two distinct photons as well as inseparability between multiple degrees of freedom. For this purpose, we subject one photon of a polarization entangled two-photon pair to a discrete-time quantum walk introducing the position subsystem of the quantum walk as a third subsystem with qudit encoding. Here we study the resulting transfer of entanglement from the polarization degree of freedom, representing qubit encoding, towards the position degree of freedom, representing quidt encoding, via partial state tomography and correlation measurements.
The preparation of high-dimensional quan- tum states is of great significance in quantum information sci- ence and technology. Compared to qubits, qudit states – de- scribing quantum systems in d-dimensional spaces – enable stronger foundational tests of quantum mechanics [1–3] and better-performing applications in secure quantum communi- cations [4–9], quantum emulation [10, 11], quantum error cor- rection [12–14], fault-tolerant quantum computation [15–19], and quantum machine learning [20–22]. Needless to say, protocols performed on systems living in Hilbert spaces of large dimension require an increasing degree of control, in light of the large number of parameters required to describe states and operations. Nonetheless, the endeav- our of preparing arbitrary qudit states has been successfully achieved in various physical platforms [11, 23–32]. However, most of these works rely on ad hoc strategies, whose specific dependence on the underpinning dynamics makes their trans- lation across different physical platforms very difficult. A very promising way to achieve the desired full inde- pendence of the physical platform, and thus a higher degree of universality, is the use of the rich dynamics offered by Quantum Walks (QWs) [33–35]. QWs, which can be thought of as the quantum counterparts of classical random walks, describe in their discrete version a high-dimensional qudit, named walker, embedded with an internal two-dimensional degree of freedom, conventionally dubbed coin. At every time step, the walker’s state moves coherently to the neighbouring sites in the lattice, conditionally to its coin state [36]. QWs have been successfully implemented [37] in systems as di- verse as trapped atoms [38] and ions [39, 40], photonic cir- cuits [41–50], and optical lattices [51]. Hence, an approach for state engineering based on their dynamics offers hope of being applicable effectively in a variety of different systems, independently of the details of the physical implementation. While the QW dynamics was previously shown to allow the engineering of specific walker’s states [52, 53], in Ref. [54] a scheme was proposed to use discrete-time QWs on a line to prepare arbitrary qudit states. This is achieved by enhanc- ing the degree of control over the walk’s dynamics through the arrangement of suitable step-dependent coin operations, which affect the coin-walker quantum correlations by de facto steering the state of the walker towards the desired final state, and finally projecting in the coin space. This last operation removes the correlations between walker and coin, thus pro- ducing a pure walker state with the desired features. In light of the large parameter space that characterizes the problem at hand, a systematic approach to the identification of the right set of coin operations and final projection is necessary. Such an analysis was presented in Ref. [54], in which a set of an- alytic conditions, together with suitable numerical optimiza- tions, was shown to guarantee the reaching of arbitrary target states with high probability. In this paper, we make use of the scheme of Ref. [54] to give the first demonstration of a state-engineering protocol based on the controlled dynamics generated by QWs. We use the orbital angular momentum (OAM) degree of freedom of single-photon states as a convenient embodiment of the walker [48, 55, 56]. OAM-based experiments offer the pos- sibility to cover Hilbert spaces of large dimensions in light of the favourable (linear) scaling of the number of optical ele- ments with the size of the walk. Moreover, the scheme al- lows for the full control of the coin operation that is key to the implementation of the walk. In order to demonstrate the ver- satility of our scheme, we focus on the interesting classes of cat-like states and spin-coherent states [57, 58]. Those classes play a critical role in the exploration of the boundaries be- tween quantum and classical physics and whose implementa- tion is, in general, still a challenging task. Furthermore, we show experimentally the capability of engineering arbitrary states. The quality of the states synthesized in our endeavours, and the relative simplicity of the experimental protocol that we have put in place, demonstrate the effectiveness of a hybrid platform for quantum state engineering. Such platform holds together a programmable quantum system, the photonic QW in the angular momentum, and classical optimization al- gorithms for finding the best evolution to reach a certain quantum target. [1] T. Ve ́rtesi, S. Pironio, and N. Brunner, Physical Review Letters 104, 060401 (2010). [2] N. Brunner, D. Cavalcanti, S. Pironio, V. Scarani, and S. Wehner, Reviews of Modern Physics 86, 419 (2014). [3] R. Lapkiewicz, P. Li, C. Schaeff, N. K. Langford, S. Ramelow, M. Wies ́niak, and A. Zeilinger, Nature 474, 490 (2011). [4] H. Bechmann-Pasquinucci and A. Peres, Physical Review Let- ters 85, 3313 (2000). [5] M. Fitzi, N. Gisin, and U. Maurer, Physical Review Letters 87, 217901 (2001). [6] N. J. Cerf, M. Bourennane, A. Karlsson, and N. Gisin, Physical Review Letters 88, 127902 (2002). [7] D. Bruß and C. Macchiavello, Physical Review Letters 88, 127901 (2002). [8] A. Acin, N. Gisin, and V. Scarani, (2003), quant-ph/0303009. [9] N. K. Langford, R. B. Dalton, M. D. Harvey, J. L. O’Brien, G. J. Pryde, A. Gilchrist, S. D. Bartlett, and A. G. White, Physical Review Letters 93, 053601 (2004). [10] I. Buluta and F. Nori, Science 326, 108 (2009). [11] M. Neeley, M. Ansmann, R. C. Bialczak, M. Hofheinz, E. Lucero, A. D. O’Connell, D. Sank, H. Wang, J. Wenner, A. N. Cleland, M. R. Geller, and J. M. Martinis, Science 325, 722 (2009). [12] I. L. Chuang, D. W. Leung, and Y. Yamamoto, Physical Review A 56, 1114 (1997). [13] G. Duclos-Cianci and D. Poulin, Physical Review A 87, 062338 (2013). [14] M. H. Michael, M. Silveri, R. T. Brierley, V. V. Albert, J. Salmilehto, L. Jiang, and S. M. Girvin, Physical Review X 6, 031006 (2016). [15] S. D. Bartlett, H. d. Guise, and B. C. Sanders, Physical Review A 65, 052316 (2002). [16] T. C. Ralph, K. J. Resch, and A. Gilchrist, Physical Review A 75, 022313 (2007). [17] B. P. Lanyon, M. Barbieri, M. P. Almeida, T. Jennewein, T. C. Ralph, K. J. Resch, G. J. Pryde, J. L. O’Brien, A. Gilchrist, and A. G. White, Nature Physics 5, 134 (2009). [18] E. T. Campbell, H. Anwar, and D. E. Browne, Physical Review X 2, 041021 (2012). [19] E. T. Campbell, Physical Review Letters 113, 230501 (2014). [20] M. Schuld, I. Sinayskiy, and F. Petruccione, Contemporary Physics 56, 172 (2015). [21] V. Dunjko and H. J. Briegel, arXiv:1709.02779. [22] J. Biamonte, P. Wittek, N. Pancotti, P. Rebentrost, N. Wiebe, and S. Lloyd, Nature 549, 195 (2017). [23] D. Leibfried, D. M. Meekhof, B. E. King, C. Monroe, W. M. Itano, and D. J. Wineland, Physical Review Letters 77, 4281 (1996). [24] M. Hofheinz, H. Wang, M. Ansmann, R. C. Bialczak, E. Lucero, M. Neeley, A. D. O’Connell, D. Sank, J. Wenner, J. M. Martinis, and A. N. Cleland, Nature 459, 546 (2009). [25] B. Anderson, H. Sosa-Martinez, C. Riofr ́ıo, I. H. Deutsch, and P. S. Jessen, Physical Review Letters 114, 240401 (2015). [26] S. P. Walborn, D. S. Lemelle, M. P. Almeida, and P. H. S. Ribeiro, Physical Review Letters 96, 090501 (2006). [27] G. Lima, L. Neves, R. Guzma ́n, E. S. Go ́mez, W. A. T. Nogueira, A. Delgado, A. Vargas, and C. Saavedra, Optics Express 19, 3542 (2011). [28] A. Rossi, G. Vallone, A. Chiuri, F. De Martini, and P. Mataloni, Physical Review Letters 102, 153902 (2009). [29] A. C. Dada, J. Leach, G. S. Buller, M. J. Padgett, and E. Andersson, Nature Physics 7, 677 (2011). [30] R. W. Heeres, P. Reinhold, N. Ofek, L. Frunzio, L. Jiang, M. H. Devoret, and R. J. Schoelkopf, Nature Communications 8, 94 (2017). [31] S. Rosenblum, Y. Y. Gao, P. Reinhold, C. Wang, C. J. Axline, L. Frunzio, S. M. Girvin, L. Jiang, M. Mirrahimi, M. H. Devoret, and R. J. Schoelkopf, Nature Comm. 9, 652 (2018). [32] Y. Chu, P. Kharel, T. Yoon, L. Frunzio, P. T. Rakich, and R. J. Schoelkopf, (2018), arXiv:1804.07426. [33] Y. Aharonov, L. Davidovich, and N. Zagury, Physical Review A 48, 1687 (1993). [34] J. Kempe, Contemporary Physics 44, 307 (2003). [35] S. E. Venegas-Andraca, Quantum Information Processing 11, 1015 (2012). [36] A. Ambainis, E. Bach, A. Nayak, A. Vishwanath, and J. Watrous, in STOC ’01 Proceedings of the thirty-third annual ACM symposium on Theory of computing (2001) pp. 37–49. [37] K. Manouchehri and J. Wang, Physical Implementation of Quantum Walks (Springer Berlin Heidelberg, Berlin, Heidelberg, 2014). [38] R. Coˆte ́, A. Russell, E. E. Eyler, and P. L. Gould, New Journal of Physics 8, 156 (2006). [39] H. Schmitz, R. Matjeschk, C. Schneider, J. Glueckert, M. Enderlein, T. Huber, and T. Schaetz, Physical Review Letters 103, 090504 (2009). [40] F. Za ̈hringer, G. Kirchmair, R. Gerritsma, E. Solano, R. Blatt, and C. F. Roos, Physical Review Letters 104, 100503 (2010). [41] H. B. Perets, Y. Lahini, F. Pozzi, M. Sorel, R. Morandotti, and Y. Silberberg, Physical Review Letters 100, 170506 (2008). [42] A. Peruzzo, M. Lobino, J. C. F. Matthews, N. Matsuda, A. Politi, K. Poulios, X.-Q. Zhou, Y. Lahini, N. Ismail, K. Wo ̈rhoff, Y. Bromberg, Y. Silberberg, M. G. Thompson, and J. L. O’Brien, Science 329, 1500 (2010). [43] M. A. Broome, A. Fedrizzi, B. P. Lanyon, I. Kassal, A. Aspuru- Guzik, and A. G. White, Phys. Rev. Lett. 104, 153602 (2010). [44] A. Schreiber, K. N. Cassemiro, V. Potocˇek, A. Ga ́bris, P. J. Mosley, E. Andersson, I. Jex, and C. Silberhorn, Physical Re- view Letters 104, 050502 (2010). [45] P. P. Rohde, A. Schreiber, M. Sˇtefanˇa ́k, I. Jex, and C. Silber- horn, New Journal of Physics 13, 013001 (2011). [46] L. Sansoni, F. Sciarrino, G. Vallone, P. Mataloni, A. Crespi, R. Ramponi, and R. Osellame, Physical Review Letters 108, 010502 (2012). [47] J. Boutari, A. Feizpour, S. Barz, C. Di Franco, M. S. Kim, W. S. Kolthammer, and I. A. Walmsley, Journal of Optics 18, 094007 (2016). [48] F. Cardano, F. Massa, H. Qassim, E. Karimi, S. Slussarenko, D. Paparo, C. de Lisio, F. Sciarrino, E. Santamato, R. W. Boyd, and L. Marrucci, Science Advances 1, e1500087 (2015). [49] F. Cardano, M. Maffei, F. Massa, B. Piccirillo, C. de Lisio, G. D. Filippis, V. Cataudella, E. Santamato, and L. Marrucci, Nature Communications 7, 11439 (2016). [50] F. Caruso, A. Crespi, A. G. Ciriolo, F. Sciarrino, and R. Osel- lame, Nature Communications 7, 11682 (2016). [51] F. Meinert, M. J. Mark, E. Kirilov, K. Lauber, P. Weinmann, M. Grobner, A. J. Daley, H.-C. Nagerl, N. Ismail, K. Wo ̈rhoff, Y. Bromberg, Y. Silberberg, M. G. Thompson, and J. L. OBrien, Science 344, 1259 (2014). [52] C. M. Chandrashekar, R. Srikanth, and R. Laflamme, Physical Review A 77, 032326 (2008). [53] H. Majury, J. Boutari, E. O’Sullivan, A. Ferraro, and M. Pater- nostro, EPJ Quant. Tech. 5, 1 (2018). [54] L. Innocenti, H. Majury, T. Giordani, N. Spagnolo, F. Sciar- rino, M. Paternostro, and A. Ferraro, Phys. Rev. A 96, 062326 (2017). [55] P.Zhang,B.H.Liu,R.F.Liu,H.R.Li,F.L.Li, andG.C. Guo, Physical Review Letters 81 (2010). [56] S. K. Goyal, F. S. Roux, A. Forbes, and T. Konrad, Physical Review Letters 110, 263602 (2013). [57] M. Brune, S. Haroche, J. M. Raimond, L. Davidovich, and N. Zagury, Phys. Rev. A 45, 5193 (1992). [58] C. Monroe, D. M. Meekhof, B. E. King, and D. J. Wineland, Science 272, 1131 (24 May 1996).