Re: [Qirg] Survey paper about the Quantum Internet Protocol Stack

[Angela Sara Cacciapuoti <[e-mail]>]

Hi Patrick,

IMO, I’m not sure this dichotomy can grasp all the opportunities offered by the laws of quantum mechanics.

Just to mention one, the quantumness can be extended to the paths in a quantum network, i.e., not only the information but also the paths along with the carriers propagate can be quantum. 
This genuine quantum phenomenon plays a paramount role for achieving unprecedented information transfer capacities, and it must be fully understood and harnessed for the Quantum Internet design.
It affects many functionalities of the network (we tried to highligth some of them in the survey as well)

Kind regards

Sara 

> Il giorno 9 giu 2022, alle ore 15:35, Gelard Patrick <[e-mail]> ha scritto:
> 
> Thank you for your answers Sara. My answers indexed by [PG]
>  
> Kind Regards
> Patrick
>  
>  
>  
> De : Angela Sara Cacciapuoti <[e-mail] <mailto:[e-mail]>> 
> Envoyé : jeudi 9 juin 2022 14:29
> À : Gelard Patrick <[e-mail] <mailto:[e-mail]>>
> Cc : [e-mail] <mailto:[e-mail]>; Jessica Illiano <[e-mail] <mailto:[e-mail]>>; Marcello Caleffi <[e-mail] <mailto:[e-mail]>>; VANDEN BOSSCHE Mathias <[e-mail] <mailto:[e-mail]>>; DE FORGES DE PARNY Laurent <[e-mail] <mailto:[e-mail]>>
> Objet : Re: [Qirg] Survey paper about the Quantum Internet Protocol Stack
>  
> Dear Patrick,
>  
> Thank you for your email and generous words.
>  
> Indeed the aim is to sollecitate discussion in our community. Diversity always helps in improving results.
>  
> Regarding your comment, it’s indeed a philosophical choice as we underlined in the final part of the article.
>  
> Specifically, if I got correctly, your vision is to avoid direct (short-range) transmissions of qubits encoding quantum information, since the communication protocols can be entirely based on entanglement exploitation (e.g., teleportation).
> [PG] Not necessarily, it is just fixing the perimeter of a quantum information network to the fact that the resource that is stored, manipulated and transmitted/exchanged is exclusively a quantum state encoded in a degree(s) of freedom of photons, which induces that the “quantum data plane” is reduced to a quantum physical layer only (level 0 of the OSI model, i.e. outside the OSI model).  The classical exchange based on an TCP/IP stack is for the management and the control plan of the quantum network.  
>  
> This is a possible choice and indeed I tend to agree on this. In other words, if a genuine quantum network is available you may not need to send quantum information via direct flying qubit transmission. You just exploit entanglement.
> [PG] Even in direct Qubit transmission, the” quantum data plane” is reduced, in my opinion, to the quantum physical layer. The transmission of classical information on a quantum information network can be seen as an implementation of a classical overlay network on a quantum underlay network.
>  
> However, other choices are possible also stemming from the particular applications/requirements.
> And the aim of Table 1 was exactly to distinguish (for the sake of generality) between qubits encoding information and qubits carrying entanglement.
>  
> In this light,  if someone choose to directly send qubits encoding information, the open question on the table is: what does quantum packet mean? Is it useful to introduce the packet concept in the QI domain? 
> [PG]Yes, what does quantum packet mean ?  
>  
> Again the answer is something related to the philosophical choice we will make in building  the Quantum Internet.
> [PG] I will read the final part of the article.
>  
>  
> Kind Regards
> Sara
>  
> Il giorno 9 giu 2022, alle ore 12:45, Gelard Patrick <[e-mail] <mailto:[e-mail]>> ha scritto:
>  
> Dear Sara,
>  
> Thank you for sharing your outstanding work, which opens a certain number of questioning/discussion.  
>  
> The first one is about Classical information vs Quantum information :
> “Specifically, bits and qubits can be considered singleton, namely, they both are self-contained entities, which – although they may be routed through the network aggregated in packets – have a meaning per-se”
>  
>  
> Classical information, encoded in bits, can be aggregated in logical packets like IP packets with header to be routed through the network. Qubit (e.g flying Qubit) can’t be aggregated in logical packets to be routed through the network.
>  
> Quantum information is above all physical information that encodes a particular physical state that will be exploited by quantum applications. For example a Qubit can encode a superposition of states (e.g A door that would be both open and closed) implementing probabilities of amplitudes that, unlike probabilities, can cancel each other out, leading to quantum interference, and consequently qualitatively new ways of processing information. Quantum interference is a physical properties use to do for example computation.  If the qubits are entangled the unit modification of one subsystem "Qubit |A>" changes the probability amplitudes of the composite system |AB> and thus the probability distribution of the whole system ( https://www.youtube.com/watch?v=-UlxHPIEVqA <https://www.youtube.com/watch?v=-UlxHPIEVqA> 2:40). For n  Qubits n qubits, |α> =  Σx∈{0,1}n αx |x> All 2n amplitudes change if we apply the Hadamard gate only to the first qubit ( Algorithms S. Dasgupta, C. H. Papadimitriou, and U. V. Vazirani : https://book.huihoo.com/pdf/algorithms/ <https://book.huihoo.com/pdf/algorithms/> )
>  
> Quantum computation is really a physical process, and a quantum information network distributes or exchanges physical information encoded in degrees of freedom of photons. We can switch photons on a network as long as we do not disturb the quantum properties they carry, which is essential for the quantum applications for which they are used (teleportation, blind computing, distributed computing, etc.).   
>  
> The QIN transfers quantum information by consuming the entanglement resource. Our vision is that there is a single end-to-end physical layer built on entanglement. ( https://arxiv.org/abs/2202.01817 <https://arxiv.org/abs/2202.01817> ).
>  
> Kind Regards
> Patrick
>  
> De : Qirg <[e-mail] <mailto:[e-mail]>> De la part de Angela Sara Cacciapuoti
> Envoyé : lundi 6 juin 2022 11:10
> À : [e-mail] <mailto:[e-mail]>
> Cc : Jessica Illiano <[e-mail] <mailto:[e-mail]>>; Marcello Caleffi <[e-mail] <mailto:[e-mail]>>
> Objet : [Qirg] Survey paper about the Quantum Internet Protocol Stack
>  
> Dear Friends and Colleagues,
>  
> I would like to share with you a survey paper about the Quantum Internet Protocol Stack
>  
> https://arxiv.org/abs/2202.10894 <https://arxiv.org/abs/2202.10894>
>  
> which has been recently accepted for publication.
>  
> I believe it could be of interest for many of you.
>  
> Any comment is much appreciated.
>  
> Kind Regards
>  
> Sara
>  
> Prof. Angela Sara Cacciapuoti, Ph.D., IEEE Senior Member
> Co-Director - FLY: Future Communications Lab    
> http://www.quantuminternet.it <http://www.quantuminternet.it/>
> Associate Professor, University of Naples Federico II
> IEEE ComSoc Distinguished Speaker
> DIETI ERASMUS Coordinator
> Area Editor:
>                         IEEE Communications Letters
> Editor/Associate Editor:
>                         IEEE Trans. on Communications
>                         IEEE Trans. on Wireless Communications
>                         IEEE Trans. on Quantum Engineering 
>                         IEEE Network
> Email: [e-mail] <mailto:[e-mail]>
> Twitter: https://twitter.com/AngelaSaraCacc <https://twitter.com/AngelaSaraCacc>