How to Draw a Circuit¶

This how-to guide walks you through drawing a circuit generated by a simple Workbench program. We will cover two ways of drawing a circuit:

1. Using the built-in draw() method.
2. Using the interactive Circuit Designer widget.

Step 1. (common to both methods) Write the program¶

Write the Workbench code following the steps outlined in How to Write a Simple Program. Your code will start with creating a QPU object.

qpu = QPU(num_qubits=4)

If you are specifying the list of filters in the constructor of the QPU, make sure to include the '>>buffer>>' filter in the list.

qpu = QPU(num_qubits=4, filters=['>>buffer>>', '>>bit-sim>>'])

Step 2a. Draw the circuit using the qpu.draw() method¶

Call the draw() method of the QPU object to draw the circuit.

qpu.draw()

If your code uses subroutines - either built-in Workbench subroutines or Qubricks you implemented yourself - call the draw() method with show_qubricks=True argument.

qpu.draw(show_qubricks=True)

Step 2b. Draw the circuit using interactive Circuit Designer widget¶

Import the circuit_designer module from psiqworkbench.integrations subpackage and call the draw function, passing it the QPU instance. Please note that for this to work, Workbench has to be installed with circuit-designer extra.

from psiqworkbench.integrations import circuit_designer

circuit_designer.draw(qpu)

You can click on registers and Qubricks in the diagram to collapse and expand them. You can also pass the expanded=True, expanded="qubricks" or expanded="registers" to control what gets expanded by default.

Example¶

The following example shows how to draw a circuit generated by the Workbench program from How to Write a Simple Program that prepares two Bell states in two different ways (using the primitive gates and using state preparation library) and then measures them.

In [1]:

from psiqworkbench import QPU, Qubits
from workbench_algorithms import ArbitraryStatePrep

# Initialize a QPU
qpu = QPU(num_qubits=4)

# Allocate qubits
reg1 = Qubits(2, "reg1", qpu=qpu)
reg2 = Qubits(2, "reg2", qpu=qpu)

# Perform the computation using primitive gates
reg1[0].had()
reg1[1].x(cond=reg1[0])

# Perform the computation using library routines
state_prep = ArbitraryStatePrep([1, 0, 0, 1])
state_prep.compute(reg2)

# Get the results
res1 = reg1.read()
res2 = reg2.read()

# Draw the circuit
qpu.draw()

# Draw the circuit with Qubricks
qpu.draw(show_qubricks=True)

from psiqworkbench import QPU, Qubits from workbench_algorithms import ArbitraryStatePrep # Initialize a QPU qpu = QPU(num_qubits=4) # Allocate qubits reg1 = Qubits(2, "reg1", qpu=qpu) reg2 = Qubits(2, "reg2", qpu=qpu) # Perform the computation using primitive gates reg1[0].had() reg1[1].x(cond=reg1[0]) # Perform the computation using library routines state_prep = ArbitraryStatePrep([1, 0, 0, 1]) state_prep.compute(reg2) # Get the results res1 = reg1.read() res2 = reg2.read() # Draw the circuit qpu.draw() # Draw the circuit with Qubricks qpu.draw(show_qubricks=True)

In [2]:

from psiqworkbench.integrations import circuit_designer

# Create Circuit Designer diagram with default setting
circuit_designer.draw(qpu)

from psiqworkbench.integrations import circuit_designer # Create Circuit Designer diagram with default setting circuit_designer.draw(qpu)

Out[2]:

In [3]:

# Create Circuit Designer diagram with both Qubricks and registers expanded
circuit_designer.draw(qpu, expanded=True)

# Create Circuit Designer diagram with both Qubricks and registers expanded circuit_designer.draw(qpu, expanded=True)

Out[3]: