GMS
class qiskit.circuit.library.GMS(num_qubits, theta)
Bases: QuantumCircuit
Global Mølmer–Sørensen gate.
Circuit symbol:
┌───────────┐
q_0: ┤0 ├
│ │
q_1: ┤1 GMS ├
│ │
q_2: ┤2 ├
└───────────┘Expanded Circuit:

The Mølmer–Sørensen gate is native to ion-trap systems. The global MS can be applied to multiple ions to entangle multiple qubits simultaneously [1].
In the two-qubit case, this is equivalent to an XX(theta) interaction, and is thus reduced to the RXXGate. The global MS gate is a sum of XX interactions on all pairs [2].
References:
[1] Sørensen, A. and Mølmer, K., Multi-particle entanglement of hot trapped ions. Physical Review Letters. 82 (9): 1835–1838. arXiv:9810040
[2] Maslov, D. and Nam, Y., Use of global interactions in efficient quantum circuit constructions. New Journal of Physics, 20(3), p.033018. arXiv:1707.06356
The class qiskit.circuit.library.generalized_gates.gms.GMS is deprecated as of Qiskit 2.1. It will be removed in Qiskit 3.0. Use the MSGate instead.
Parameters
- num_qubits (int) – width of gate.
- theta (list[list[float]] | np.ndarray) – a num_qubits x num_qubits symmetric matrix of interaction angles for each qubit pair. The upper triangle is considered.
Attributes
name
Type: str
A human-readable name for the circuit.
Example
from qiskit import QuantumCircuit
qc = QuantumCircuit(2, 2, name="my_circuit")
print(qc.name)my_circuit