plot

Plot quantum circuit or composite gate

Since R2023a

Installation Required: This functionality requires MATLAB Support Package for Quantum Computing.

Syntax

plot(c)

plot(c,Name=Value)

plot(parent,___)

p = plot(___)

Description

plot(c) plots the quantum circuit or composite gate c.

plot(c,Name=Value) specifies options using one or more name-value arguments. For example, plot(c,QubitBlocks=[5 3]) separates blocks of 5 and 3 qubits with a red dashed line in the plot.

plot(parent,___) plots into the specified parent container instead of the current container. The argument parent can precede any of the input argument combinations in the previous syntaxes.

p = plot(___) returns a QuantumCircuitChart object. Use this object to inspect and modify the properties of the plotted circuit. For a list of properties, see QuantumCircuitChart Properties.

Examples

Create and Plot Quantum Circuit

Create a quantum circuit that consists of a Hadamard gate and a controlled X gate to entangle two qubits.

gates = [hGate(1); cxGate(1,2)];
c = quantumCircuit(gates);

Plot the circuit.

plot(c)

Plot Quantum Circuit with Lines Separating Qubit Blocks

Create a quantum circuit that consists of four controlled controlled X (CCX) gates.

gates = ccxGate([1 3 4 5],[2 6 7 8],[6 7 8 9]);
c = quantumCircuit(gates);

Plot the circuit with lines separating the qubit blocks. The qubit blocks to be separated are the first 5 qubits, followed by the next 3 qubits, and the last 1 qubit. The first 5 qubits are the first control qubits of each of the four CCX gates as well as the second control qubit of the first gate. The next 3 qubits are the second control qubits of the rest of the CCX gates. And the last 1 qubit is the final target qubit that holds the result of applying the last CCX gate.

plot(c,QubitBlocks=[5 3 1])

Plot Quantum Circuit That Contains Composite Gates

Create an array of inner gates consisting of a Hadamard gate and a controlled X gate to entangle two qubits.

gates = [hGate(1); cxGate(1,2)];

Construct two composite gates from the array of inner gates. Name the two composite gates as "bell". The first composite gate acts on qubits 1 and 3 of the outer circuit containing this gate. The second composite gate acts on qubits 2 and 4 of the outer circuit containing this gate.

cg1 = compositeGate(gates,[1 3],Name="bell");
cg2 = compositeGate(gates,[2 4],Name="bell");

Create a quantum circuit that contains these two composite gates.

circuit = quantumCircuit([cg1; cg2])

circuit = 

  quantumCircuit with properties:

    NumQubits: 4
        Gates: [2×1 quantum.gate.CompositeGate]
         Name: ""

Plot the circuit.

plot(circuit)

In a circuit diagram, each solid horizontal line represents a qubit. The top line is a qubit with index 1 and the remaining lines from top to bottom are labeled sequentially. In this example, the plotted circuit consists of four qubits with indices 1, 2, 3, and 4. The plot shows that qubits 1 and 3 of the circuit are mapped to qubits 1 and 2 of the inner gates of the first composite gate, and qubits 2 and 4 of the circuit are mapped to qubits 1 and 2 of the inner gates of the second composite gate.

Click one of the composite gate blocks in the plot. A new figure showing the internal gates of the composite gate appears.

Specify Location of Qubit Line Labels

Create and plot a quantum circuit that consists of a Hadamard gate and a controlled X gate to entangle two qubits. Return the QuantumCircuitChart object by specifying an output argument to plot.

gates = [hGate(1); cxGate(1,2)];
c = quantumCircuit(gates);
p = plot(c);

Display qubit labels on the left by modifying properties of the chart object.

p.QubitLabelLocation = "left";

Input Arguments

c — Quantum circuit or composite gate

quantumCircuit object | CompositeGate object

Quantum circuit or composite gate, specified as a quantumCircuit object or CompositeGate object.

parent — Parent container

Figure object (default) | Panel object | Tab object | TiledChartLayout object

Parent container of the chart, specified as a Figure, Panel, Tab, or TiledChartLayout object. If you do not specify a parent container, then plot uses the current container.

Name-Value Arguments

Specify optional pairs of arguments as Name1=Value1,...,NameN=ValueN, where Name is the argument name and Value is the corresponding value. Name-value arguments must appear after other arguments, but the order of the pairs does not matter.

Example: p = plot(c,NumRows=2,QubitLabelLocation="left")

The quantum circuit chart properties listed here are only a subset. For a complete list, see QuantumCircuitChart Properties.

QubitBlocks — Block sizes to separate in plot

integer vector

Block sizes to separate in the plot, specified as a vector of integers. Each element of the vector specifies the size of one block of qubits. The sum of the block sizes must equal the number of qubits in the circuit.

Example: [3 2 1]

NumRows — Number of rows to wrap circuit over

positive integer scalar

Number of rows to wrap the circuit over, specified as a positive integer scalar. If you do not specify NumRows, then plot automatically determines the number of rows.

QubitLabelLocation — Location of qubit line labels

"left" | "right" | "none" | "both"

Location of qubit line labels, specified as "left", "right", "none", or "both". If you do not specify QubitLabelLocation, then plot automatically determines the label locations.

Tips

• On a plotted quantum circuit or composite gate, you can move your mouse over the gate symbols (on the corners of the box symbol or on the markers of the gate symbol) to show additional information about the individual gates. This information includes the gate name, the gate index in the circuit, and the specified angle for the gate operation.

• You can click on a plotted composite gate to open a new figure with the internal gates of the composite gate.

Version History

Introduced in R2023a

R2023b: Control circuit plot appearance and behavior

When you plot a circuit or composite gate with the plot method, you can now specify an output argument to return a QuantumCircuitChart object. Set properties of the object to control the appearance and behavior of the circuit plot. See QuantumCircuitChart Properties for more information.