"""Transmon qubit components."""
from __future__ import annotations
import gdsfactory as gf
from gdsfactory.component import Component
from gdsfactory.typings import LayerSpec
from qpdk.tech import LAYER
[docs]
@gf.cell_with_module_name
def transmon(
pad_width: float = 200.0,
pad_height: float = 100.0,
pad_gap: float = 6.0,
junction_width: float = 0.15,
junction_height: float = 0.3,
island_width: float = 10.0,
island_height: float = 4.0,
layer_metal: LayerSpec = LAYER.M1_DRAW,
layer_junction: LayerSpec = LAYER.JJ_AREA,
layer_island: LayerSpec = LAYER.M1_DRAW,
port_type: str = "electrical",
) -> Component:
"""Creates a transmon qubit with Josephson junction.
A transmon qubit consists of two capacitor pads connected by a Josephson junction.
The junction creates an anharmonic oscillator that can be used as a qubit.
Args:
pad_width: Width of each capacitor pad in μm.
pad_height: Height of each capacitor pad in μm.
pad_gap: Gap between the two pads in μm.
junction_width: Width of the Josephson junction in μm.
junction_height: Height of the Josephson junction in μm.
island_width: Width of the central island in μm.
island_height: Height of the central island in μm.
layer_metal: Layer for the metal pads.
layer_junction: Layer for the Josephson junction.
layer_island: Layer for the central island.
port_type: Type of port to add to the component.
Returns:
Component: A gdsfactory component with the transmon geometry.
"""
c = Component()
# Create left capacitor pad
left_pad = gf.components.rectangle(
size=(pad_width, pad_height),
layer=layer_metal,
port_type=port_type,
)
left_pad_ref = c.add_ref(left_pad)
left_pad_ref.move((-pad_width - pad_gap / 2, -pad_height / 2))
# Create right capacitor pad
right_pad = gf.components.rectangle(
size=(pad_width, pad_height),
layer=layer_metal,
port_type=port_type,
)
right_pad_ref = c.add_ref(right_pad)
right_pad_ref.move((pad_gap / 2, -pad_height / 2))
# Create central island
island = gf.components.rectangle(
size=(island_width, island_height),
layer=layer_island,
)
island_ref = c.add_ref(island)
island_ref.move((-island_width / 2, -island_height / 2))
# Create Josephson junction
junction = gf.components.rectangle(
size=(junction_width, junction_height),
layer=layer_junction,
)
junction_ref = c.add_ref(junction)
junction_ref.move((-junction_width / 2, -junction_height / 2))
# Add connection lines from pads to island
# Only add connections if there is a gap between island and pads
connection_width = abs(pad_gap / 2 - island_width / 2)
if pad_gap / 2 > island_width / 2:
left_connection = gf.components.rectangle(
size=(connection_width, junction_height / 2),
layer=layer_metal,
)
left_conn_ref = c.add_ref(left_connection)
left_conn_ref.move((-pad_gap / 2, -junction_height / 4))
right_connection = gf.components.rectangle(
size=(connection_width, junction_height / 2),
layer=layer_metal,
)
right_conn_ref = c.add_ref(right_connection)
right_conn_ref.move((island_width / 2, -junction_height / 4))
# Add ports for connections
c.add_port(
name="left_pad",
center=(-pad_width - pad_gap / 2, 0),
width=pad_height,
orientation=180,
layer=layer_metal,
)
c.add_port(
name="right_pad",
center=(pad_width + pad_gap / 2, 0),
width=pad_height,
orientation=0,
layer=layer_metal,
)
# Add metadata
c.info["qubit_type"] = "transmon"
c.info["pad_width"] = pad_width
c.info["pad_height"] = pad_height
c.info["pad_gap"] = pad_gap
c.info["junction_area"] = junction_width * junction_height
return c
[docs]
@gf.cell_with_module_name
def transmon_circular(
pad_radius: float = 100.0,
pad_gap: float = 6.0,
junction_width: float = 0.15,
junction_height: float = 0.3,
island_radius: float = 5.0,
layer_metal: LayerSpec = LAYER.M1_DRAW,
layer_junction: LayerSpec = LAYER.JJ_AREA,
layer_island: LayerSpec = LAYER.M1_DRAW,
port_type: str = "electrical",
) -> Component:
"""Creates a circular transmon qubit with Josephson junction.
A circular variant of the transmon qubit with circular capacitor pads.
Args:
pad_radius: Radius of each circular capacitor pad in μm.
pad_gap: Gap between the two pads in μm.
junction_width: Width of the Josephson junction in μm.
junction_height: Height of the Josephson junction in μm.
island_radius: Radius of the central circular island in μm.
layer_metal: Layer for the metal pads.
layer_junction: Layer for the Josephson junction.
layer_island: Layer for the central island.
port_type: Type of port to add to the component.
Returns:
Component: A gdsfactory component with the circular transmon geometry.
"""
c = Component()
# Create left circular pad
left_pad = gf.components.circle(
radius=pad_radius,
layer=layer_metal,
)
left_pad_ref = c.add_ref(left_pad)
left_pad_ref.move((-pad_radius - pad_gap / 2, 0))
# Create right circular pad
right_pad = gf.components.circle(
radius=pad_radius,
layer=layer_metal,
)
right_pad_ref = c.add_ref(right_pad)
right_pad_ref.move((pad_radius + pad_gap / 2, 0))
# Create central circular island
island = gf.components.circle(
radius=island_radius,
layer=layer_island,
)
c.add_ref(island)
# Create Josephson junction
junction = gf.components.rectangle(
size=(junction_width, junction_height),
layer=layer_junction,
)
junction_ref = c.add_ref(junction)
junction_ref.move((-junction_width / 2, -junction_height / 2))
# Add connection lines from pads to island
# Only add connections if there is a gap between island and pads
connection_width = abs(pad_gap / 2 - island_radius)
if pad_gap / 2 > island_radius:
left_connection = gf.components.rectangle(
size=(connection_width, junction_height / 2),
layer=layer_metal,
)
left_conn_ref = c.add_ref(left_connection)
left_conn_ref.move((-pad_gap / 2, -junction_height / 4))
right_connection = gf.components.rectangle(
size=(connection_width, junction_height / 2),
layer=layer_metal,
)
right_conn_ref = c.add_ref(right_connection)
right_conn_ref.move((island_radius, -junction_height / 4))
# Add ports for connections
c.add_port(
name="left_pad",
center=(-2 * pad_radius - pad_gap / 2, 0),
width=2 * pad_radius,
orientation=180,
layer=layer_metal,
)
c.add_port(
name="right_pad",
center=(2 * pad_radius + pad_gap / 2, 0),
width=2 * pad_radius,
orientation=0,
layer=layer_metal,
)
# Add metadata
c.info["qubit_type"] = "transmon_circular"
c.info["pad_radius"] = pad_radius
c.info["pad_gap"] = pad_gap
c.info["junction_area"] = junction_width * junction_height
return c
if __name__ == "__main__":
from qpdk import PDK
PDK.activate()
# c = transmon()
c = transmon_circular()
c.show()
