GMS¶
- class GMS(num_qubits, theta)[source]¶
Bases :
QuantumCircuit
Global Mølmer–Sørensen gate.
Circuit symbol:
┌───────────┐ q_0: ┤0 ├ │ │ q_1: ┤1 GMS ├ │ │ q_2: ┤2 ├ └───────────┘
Expanded Circuit:
(
Source code
,png
,hires.png
,pdf
)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].
\[GMS(\chi_{12}, \chi_{13}, ..., \chi_{n-1 n}) = exp(-i \sum_{i=1}^{n} \sum_{j=i+1}^{n} X{\otimes}X \frac{\chi_{ij}}{2})\]References:
[1] Sørensen, A. and Mølmer, K., Multi-particle entanglement of hot trapped ions. Physical Review Letters. 82 (9): 1835–1838. arXiv:9810040
[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
Create a new Global Mølmer–Sørensen (GMS) gate.
- Paramètres
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.
- Type renvoyé
List
[AncillaQubit
]
- calibrations¶
Return calibration dictionary.
The custom pulse definition of a given gate is of the form
{'gate_name': {(qubits, params): schedule}}
- Type renvoyé
dict
- clbits¶
Returns a list of classical bits in the order that the registers were added.
- Type renvoyé
List
[Clbit
]
- data¶
Return the circuit data (instructions and context).
- Renvoie
a list-like object containing the
CircuitInstruction
s for each instruction.- Type renvoyé
QuantumCircuitData
- extension_lib = 'include "qelib1.inc";'¶
- global_phase¶
Return the global phase of the circuit in radians.
- Type renvoyé
Union
[ParameterExpression
,float
]
- header = 'OPENQASM 2.0;'¶
- instances = 2021¶
- 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.- Type renvoyé
dict
- num_ancillas¶
Return the number of ancilla qubits.
- Type renvoyé
int
- num_clbits¶
Return number of classical bits.
- Type renvoyé
int
- num_parameters¶
The number of parameter objects in the circuit.
- Type renvoyé
int
- num_qubits¶
Return number of qubits.
- Type renvoyé
int
- op_start_times¶
Return a list of operation start times.
This attribute is enabled once one of scheduling analysis passes runs on the quantum circuit.
- Type renvoyé
List
[int
]- Renvoie
List of integers representing instruction start times. The index corresponds to the index of instruction in
QuantumCircuit.data
.- Lève
AttributeError – When circuit is not scheduled.
- parameters¶
The parameters defined in the circuit.
This attribute returns the
Parameter
objects in the circuit sorted alphabetically. Note that parameters instantiated with aParameterVector
are still sorted numerically.Exemples
The snippet below shows that insertion order of parameters does not matter.
>>> from qiskit.circuit import QuantumCircuit, Parameter >>> a, b, elephant = Parameter("a"), Parameter("b"), Parameter("elephant") >>> circuit = QuantumCircuit(1) >>> circuit.rx(b, 0) >>> circuit.rz(elephant, 0) >>> circuit.ry(a, 0) >>> circuit.parameters # sorted alphabetically! ParameterView([Parameter(a), Parameter(b), Parameter(elephant)])
Bear in mind that alphabetical sorting might be unituitive when it comes to numbers. The literal « 10 » comes before « 2 » in strict alphabetical sorting.
>>> from qiskit.circuit import QuantumCircuit, Parameter >>> angles = [Parameter("angle_1"), Parameter("angle_2"), Parameter("angle_10")] >>> circuit = QuantumCircuit(1) >>> circuit.u(*angles, 0) >>> circuit.draw() ┌─────────────────────────────┐ q: ┤ U(angle_1,angle_2,angle_10) ├ └─────────────────────────────┘ >>> circuit.parameters ParameterView([Parameter(angle_1), Parameter(angle_10), Parameter(angle_2)])
To respect numerical sorting, a
ParameterVector
can be used.>>> from qiskit.circuit import QuantumCircuit, Parameter, ParameterVector >>> x = ParameterVector("x", 12) >>> circuit = QuantumCircuit(1) >>> for x_i in x: ... circuit.rx(x_i, 0) >>> circuit.parameters ParameterView([ ParameterVectorElement(x[0]), ParameterVectorElement(x[1]), ParameterVectorElement(x[2]), ParameterVectorElement(x[3]), ..., ParameterVectorElement(x[11]) ])
- Type renvoyé
ParameterView
- Renvoie
The sorted
Parameter
objects in the circuit.
- prefix = 'circuit'¶