The quantum teleportation allows one to teleport quantum information, but to fully recover it one needs to send 2 bits of classical information over a classical channel per each teleported qubit?
Quantum teleportation is a fundamental concept in quantum information theory that enables the transfer of quantum information from one location to another, without physically transporting the quantum state itself. This process involves the entanglement of two particles and the transmission of classical information to reconstruct the quantum state at the receiving end.
In quantum teleportation, three particles are involved: the sender's qubit (the quantum information to be teleported), one half of an entangled pair shared between the sender and receiver (Bell pair), and the receiver's qubit (the particle at the receiving end). The process starts with the sender performing a joint measurement on their qubit and the Bell pair. This measurement collapses the entangled state of the Bell pair and provides two classical bits of information to be sent to the receiver.
The two classical bits received by the receiver convey information about the necessary operations to be performed on the receiver's qubit to reconstruct the sender's original qubit state. By applying these operations, the receiver can transform their qubit into an identical state to the sender's initial qubit, effectively teleporting the quantum information.
The requirement of sending two classical bits for each qubit teleported is a important aspect of quantum teleportation. These classical bits are essential for the receiver to perform the correct operations to recover the quantum state reliably. Without this classical information, the quantum state cannot be accurately reconstructed at the receiving end, leading to the loss of quantum information.
To illustrate this concept, consider a scenario where Alice wants to teleport a qubit to Bob. If Alice has a qubit in an unknown state |ψ⟩ = α|0⟩ + β|1⟩, where α and β are complex numbers representing probability amplitudes, she entangles her qubit with her half of the Bell pair. After performing a joint measurement, Alice obtains two classical bits that she sends to Bob. Bob then uses these classical bits to apply the necessary quantum gates to his qubit, resulting in the state α|0⟩ + β|1⟩ being successfully teleported from Alice to Bob.
Quantum teleportation allows for the transfer of quantum information between particles, but the complete recovery of this information at the receiving end necessitates the transmission of two classical bits per teleported qubit to guide the reconstruction process accurately.
Other recent questions and answers regarding EITC/QI/QIF Quantum Information Fundamentals:
- Is the quantum Fourier transform exponentially faster than a classical transform, and is this why it can make difficult problems solvable by a quantum computer?
- What it means for mixed state qubits going below the Bloch sphere surface?
- What was the history of the double slit experment and how it relates to wave mechanics and quantum mechanics development?
- Are amplitudes of quantum states always real numbers?
- How the quantum negation gate (quantum NOT or Pauli-X gate) operates?
- Why is the Hadamard gate self-reversible?
- If you measure the 1st qubit of the Bell state in a certain basis and then measure the 2nd qubit in a basis rotated by a certain angle theta, the probability that you will obtain projection to the corresponding vector is equal to the square of sine of theta?
- How many bits of classical information would be required to describe the state of an arbitrary qubit superposition?
- How many dimensions has a space of 3 qubits?
- Will the measurement of a qubit destroy its quantum superposition?
View more questions and answers in EITC/QI/QIF Quantum Information Fundamentals