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GMS

GMS(num_qubits, theta)

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Bases: qiskit.circuit.quantumcircuit.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].

GMS(χ12,χ13,...,χn1n)=exp(ii=1nj=i+1nXXχij2)GMS(\chi_{12}, \chi_{13}, ..., \chi_{n-1 n}) = exp(-i \sum_{i=1}^{n} \sum_{j=i+1}^{n} X{\otimes}X \frac{\chi_{ij}}{2})

References:

[1] Sørensen, A. and Mølmer, K., Multi-particle entanglement of hot trapped ions. Physical Review Letters. 82 (9): 1835–1838. arXiv:9810040(opens in a new tab)

[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(opens in a new tab)

Create a new Global Mølmer–Sørensen (GMS) gate.

Parameters

  • num_qubits (int) – width of gate.
  • theta (Union[List[List[float]], ndarray]) – a num_qubits x num_qubits symmetric matrix of interaction angles for each qubit pair. The upper triangle is considered.

Attributes

ancillas

Returns a list of ancilla bits in the order that the registers were added.

Return type

List[AncillaQubit]

calibrations

Return calibration dictionary.

The custom pulse definition of a given gate is of the form

{‘gate_name’: {(qubits, params): schedule}}

Return type

dict

clbits

Returns a list of classical bits in the order that the registers were added.

Return type

List[Clbit]

data

Return the circuit data (instructions and context).

Returns

a list-like object containing the tuples for the circuit’s data.

Each tuple is in the format (instruction, qargs, cargs), where instruction is an Instruction (or subclass) object, qargs is a list of Qubit objects, and cargs is a list of Clbit objects.

Return type

QuantumCircuitData

extension_lib

= 'include "qelib1.inc";'

global_phase

Return the global phase of the circuit in radians.

Return type

Union[ParameterExpression, float]

= 'OPENQASM 2.0;'

instances

= 9

metadata

The user provided metadata associated with the circuit

The metadata for the circuit is a user provided dict of metadata for the circuit. It will not be used to influence the execution or operation of the circuit, but it is expected to be passed between all transforms of the circuit (ie transpilation) and that providers will associate any circuit metadata with the results it returns from execution of that circuit.

Return type

dict

num_ancillas

Return the number of ancilla qubits.

Return type

int

num_clbits

Return number of classical bits.

Return type

int

num_parameters

Convenience function to get the number of parameter objects in the circuit.

Return type

int

num_qubits

Return number of qubits.

Return type

int

parameters

Convenience function to get the parameters defined in the parameter table.

Return type

ParameterView

prefix

= 'circuit'

qubits

Returns a list of quantum bits in the order that the registers were added.

Return type

List[Qubit]

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