Week 17 - my notes
Table of Contents
Week 17 - Superdense Coding
Bell States
- They are the most entangled states of a two-qubit circuits
- Each Bell state has its own circuit
Setting up the protocol
- Alice and Bob need to create and share the first Bell state (entangle two qubits)
- Create a decision scheme which assigns a message to each Bell state.
- The scheme usually is: 00 - \[|\beta00\rangle\], 01 - \[|\beta01\rangle\], 10 - \[|\beta10\rangle\], 11 - \[|\beta11\rangle\]
Introduction to Superdense Coding
- It has 3 phases:
- Sharing (The party entangles two qubits, each one taking one qubit)
- Sending (Alice applies a circuit to her qubit to create a bell state between the entangled pair. Then, she sends her qubit to Bob)
- Measuring (Bob measures his qubit, and can see which Bell state the qubits became. Then, he uses the decision scheme to dechiper the message)
Resources
Qiskit textbook page on superdense coding URL: https://qiskit.org/textbook/ch-algorithms/superdense-coding.html
Implementation of superdense coding URL:https://www.osti.gov/pages/servlets/purl/1343530
Sharing of entanglement over long distances URL: https://physicsworld.com/a/entanglement-distributed-over-1200-km-by-quantum-satellite/