create_tfim_circuit function

create_tfim_circuit(n_qubits, theta_z, theta_x, periodic_boundary=False)

Constructs a quantum circuit that simulates the Transverse Field Ising Model (TFIM) on a chain of qubits. The circuit includes ZZ interactions and transverse field applications, with an option for periodic boundary conditions.

Parameters:

  • n_qubits (int) – The number of qubits, representing spins in the TFIM chain.

  • theta_z (float) – The angle parameter for the ZZ interaction gates (RZ rotations).

  • theta_x (float) – The angle parameter for the RX transverse field gates.

  • periodic_boundary (bool, optional) – Flag to determine whether to apply periodic boundary conditions, connecting the last qubit to the first.

Returns:

The quantum circuit representing the TFIM simulation.

Return type:

QuantumCircuit

This function uses the Qiskit library to create a circuit with controlled-X (CX) and rotation gates (RZ, RX) to represent the interactions in the TFIM. It supports the application of periodic boundary conditions to model a closed spin chain.

Example Usage

The following example demonstrates the creation of a TFIM circuit for 4 qubits with specified theta parameters and periodic boundary conditions:

# Define the number of qubits and interaction parameters
n_qubits = 4
theta_z = 1.0  # ZZ interaction strength
theta_x = 1.5  # Transverse field strength

# Create the TFIM circuit with periodic boundary conditions
qc = create_tfim_circuit(n_qubits, theta_z, theta_x, periodic_boundary=True)

# Print the circuit for inspection
print(qc)

This script will output a quantum circuit for the TFIM model that includes periodic boundary conditions.