Quantum Entanglement in Quantum Computing

Introduction

Quantum entanglement is a fundamental phenomenon in quantum mechanics where two or more particles become correlated in such a way that the state of one particle cannot be described independently of the state of the other(s), even when the particles are separated by a large distance. This feature is crucial for quantum computing, enabling capabilities like quantum teleportation and superdense coding.

Key Concepts

• Quantum Bit (Qubit): The basic unit of quantum information, analogous to a classical bit but can exist in superposition.
• Superposition: A principle that allows quantum systems to be in multiple states at once.
• Measurement: The process of observing a quantum state, which collapses the superposition into one of the possible outcomes.
• Non-locality: Entangled particles affect each other instantaneously, regardless of distance, defying classical intuitions about locality.
• Bell's Theorem: A fundamental result that demonstrates the difference between quantum mechanics and classical physics regarding entangled particles.

Entanglement Process

Entanglement can be realized through various processes, including:

1. Two particles are generated in an entangled state, such as through spontaneous parametric down-conversion.
2. The quantum state of the system is described by a joint wave function.
3. When measuring one particle, the state of the other particle is instantaneously determined.
4. This correlation persists no matter the distance between the particles.

graph TD;
    A[Start] --> B[Generate Entangled Particles]
    B --> C[Describe Joint Wave Function]
    C --> D[Measure Particle 1]
    D --> E[Determine State of Particle 2]
    E --> F[End]
                

Code Example

Below is an example of how to create entangled states using the Python library Qiskit:

from qiskit import QuantumCircuit, Aer, execute

# Create a Quantum Circuit with 2 qubits
qc = QuantumCircuit(2)

# Create a Bell state (entangled state)
qc.h(0)  # Apply Hadamard gate to qubit 0
qc.cx(0, 1)  # Apply CNOT gate

# Measure the qubits
qc.measure_all()

# Execute the circuit
backend = Aer.get_backend('qasm_simulator')
result = execute(qc, backend, shots=1000).result()
counts = result.get_counts()

print(counts)
                

FAQ