ETD

Archivio digitale delle tesi discusse presso l'Università di Pisa

Tesi etd-09032021-145319


Tipo di tesi
Tesi di laurea magistrale
Autore
BACCIOTTINI, LEONARDO
URN
etd-09032021-145319
Titolo
Encoding and extracting a classical Internet packet from a qubit: issues, algorithms and their performance evaluation
Dipartimento
INGEGNERIA DELL'INFORMAZIONE
Corso di studi
COMPUTER ENGINEERING
Relatori
relatore Prof. Mingozzi, Enzo
relatore Prof. Anastasi, Giuseppe
relatore Prof. Lenzini, Luciano
Parole chiave
  • Chernoff bound
  • violation of Holevo bound
  • deutschian CTCs
  • simulation
  • closed timelike curve
  • retrieval of an n-bit string from a single qubit
  • quantum algorithm
  • quantum Internet
Data inizio appello
24/09/2021
Consultabilità
Non consultabile
Data di rilascio
24/09/2024
Riassunto
The Quantum Internet has been conceived as a disruptive communication paradigm
to transfer qubit states among different computers so as to support applications
which are out of reach for the current Internet. Using qubits to convey classical
internet packets (basically n-bit strings of classical information) through the
Quantum Internet is a challenging issue which is thoroughly investigated in the
thesis. An infinite amount of information can be encoded in the amplitudes of a
qubit. However this information cannot be accessed easily: when a qubit is
measured it collapses either on 0 or 1, losing everything that was stored inside.
Holevo’s theorem sets an upper bound, stating that only one classical bit of
information can be reliably extracted from a qubit and this looks pretty bad for our
purposes. The transmission of two bits via a single qubit is made possible by
the Superdense coding protocol. However the bit length of a packet is much higher
than 2!
The violation of the Holevo bound, and thus the retrieval of an n-bit string from a
single qubit, is made possible by the Deutschian closed timelike curve (D-CTC). In
this thesis we focus on an iterative algorithm to simulate the presence of a D-CTC
and extract n-bits of information from a qubit state. We evaluate the performances
of this algorithm and compare its outcomes with a theoretical limit, called the
Quantum Chernoff bound. The insights gained during the performance analysis allowed us to
formulate a number of coding proposals which outperform those of the assessed
algorithm.
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