"""Transmons with resonators coupled."""
from __future__ import annotations
import uuid
from functools import partial
import gdsfactory as gf
from gdsfactory.component import Component
from gdsfactory.typings import ComponentSpec, CrossSectionSpec
from klayout.db import DCplxTrans
from qpdk.cells.capacitor import plate_capacitor_single
from qpdk.cells.resonator import (
resonator_quarter_wave_bend_start,
)
from qpdk.cells.waveguides import coupler_straight
from qpdk.helper import show_components
from qpdk.tech import route_bundle_cpw
def _transmon_with_resonator_base(
qubit: ComponentSpec = "double_pad_transmon_with_bbox",
resonator: ComponentSpec = partial(
resonator_quarter_wave_bend_start, length=4000, meanders=6
),
resonator_meander_start: tuple[float, float] = (-700, -1300),
resonator_length: float = 5000.0,
resonator_meanders: int = 5,
resonator_bend_spec: ComponentSpec = "bend_circular",
resonator_cross_section: CrossSectionSpec = "cpw",
resonator_open_start: bool = False,
resonator_open_end: bool = True,
coupler: ComponentSpec = partial(plate_capacitor_single, width=20, length=394),
qubit_rotation: float = 90,
coupler_port: str = "left_pad",
coupler_offset: tuple[float, float] = (-45, 0),
with_probeline: bool = True,
probeline_coupler: ComponentSpec = coupler_straight,
probeline_coupling_gap: float = 16.0,
probeline_coupling_length: float | None = None,
) -> Component:
"""Base function for creating a transmon coupled to a resonator, optionally with a probeline.
Args:
qubit: Qubit component.
resonator: Resonator component.
resonator_meander_start: (x, y) position of the start of the resonator meander.
resonator_length: Length of the resonator in µm.
resonator_meanders: Number of meander sections for the resonator.
resonator_bend_spec: Specification for the bend component used in meanders.
resonator_cross_section: Cross-section specification for the resonator.
resonator_open_start: If True, adds an etch section at the start of the resonator.
resonator_open_end: If True, adds an etch section at the end of the resonator.
coupler: Coupler spec.
qubit_rotation: Rotation angle for the qubit in degrees.
coupler_port: Name of the qubit port to position the coupler relative to.
coupler_offset: (x, y) offset for the coupler position.
with_probeline: Whether to include a probeline coupler.
probeline_coupler: Component spec for the probeline coupling section.
probeline_coupling_gap: Gap between the resonator and probeline
waveguides in the coupling section in µm.
probeline_coupling_length: Length of the coupling section in µm.
If None, it will be calculated based on the distance from the
resonator meander start to the coupler position.
"""
c = Component()
qubit_ref = c << gf.get_component(qubit)
qubit_ref.rotate(qubit_rotation)
coupler_ref = c << gf.get_component(coupler)
# Position coupler close to qubit
coupler_ref.transform(
qubit_ref.ports[coupler_port].dcplx_trans
* DCplxTrans.R180
* DCplxTrans(*coupler_offset)
)
coupling_o1_port = None
coupling_o2_port = None
if with_probeline:
if probeline_coupling_length is None:
xs = gf.get_cross_section(resonator_cross_section)
radius = getattr(xs, "radius", 100.0)
probeline_coupling_length = (
abs(resonator_meander_start[0] - coupler_ref.ports["o1"].x) - radius
)
if probeline_coupling_length <= 0:
raise ValueError(
f"Auto-computed probeline_coupling_length={probeline_coupling_length:.1f} µm is non-positive. "
"Increase the distance between resonator_meander_start and the coupler, or pass an explicit probeline_coupling_length."
)
# Create probeline coupling.
cs_ref = c << gf.get_component(
probeline_coupler,
gap=probeline_coupling_gap,
length=probeline_coupling_length,
cross_section=resonator_cross_section,
)
# Position the coupler_straight so that o2 (bottom left) is at
# the resonator_meander_start position.
cs_ref.move(
(
resonator_meander_start[0] - cs_ref.ports["o2"].x,
resonator_meander_start[1] - cs_ref.ports["o2"].y,
)
)
route_start_port = cs_ref.ports["o3"]
resonator_connect_port = cs_ref.ports["o2"]
coupling_o1_port = cs_ref.ports["o1"]
coupling_o2_port = cs_ref.ports["o4"]
added_length = probeline_coupling_length
else:
# We need a port to start the route from, so we create a dummy port
dummy = gf.Component(name=f"dummy_route_start_{uuid.uuid4().hex[:8]}")
dummy.add_port(
name="o1",
center=(0, 0),
width=10,
orientation=180,
cross_section=resonator_cross_section,
)
dummy_port = dummy.ports["o1"].copy()
dummy_port.center = resonator_meander_start
dummy_port.orientation = 0
route_start_port = dummy_port
resonator_connect_port = None
added_length = 0.0
# Route from meander start to the plate capacitor
routes = route_bundle_cpw(
component=c,
ports1=[route_start_port],
ports2=[coupler_ref.ports["o1"]],
auto_taper=False,
)
route = routes[0]
# Create resonator, accounting for both the route and coupling lengths
resonator_ref = c << gf.get_component(
resonator,
length=resonator_length - route.length * c.kcl.dbu - added_length,
meanders=resonator_meanders,
bend_spec=resonator_bend_spec,
cross_section=resonator_cross_section,
open_start=resonator_open_start,
open_end=resonator_open_end,
)
if with_probeline:
# Connect the resonator's shorted end to the coupler_straight's top-left port.
resonator_ref.connect("o1", resonator_connect_port)
else:
# Connect to the start of the route
resonator_ref.connect("o1", route.instances[0].ports["o1"])
c.info["qubit_type"] = qubit_ref.cell.info.get("qubit_type")
c.info["resonator_type"] = resonator_ref.cell.info.get("resonator_type")
c.info["coupler_type"] = coupler_ref.cell.info.get("coupler_type")
c.info["length"] = (
resonator_ref.cell.info.get("length") + route.length * c.kcl.dbu + added_length
)
c.add_ports(qubit_ref.ports.filter(regex=r"junction"))
if with_probeline and coupling_o1_port:
c.add_port("coupling_o1", port=coupling_o1_port)
c.add_port("coupling_o2", port=coupling_o2_port)
c.add_port(
port=resonator_ref.ports["o1"],
port_type="placement",
)
return c
[docs]
@gf.cell
def transmon_with_resonator_and_probeline(
qubit: ComponentSpec = "double_pad_transmon_with_bbox",
resonator: ComponentSpec = partial(
resonator_quarter_wave_bend_start, length=4000, meanders=6
),
resonator_meander_start: tuple[float, float] = (-900, -1200),
resonator_length: float = 5000.0,
resonator_meanders: int = 5,
resonator_bend_spec: ComponentSpec = "bend_circular",
resonator_cross_section: CrossSectionSpec = "cpw",
resonator_open_start: bool = False,
resonator_open_end: bool = True,
coupler: ComponentSpec = partial(plate_capacitor_single, width=20, length=394),
qubit_rotation: float = 90,
coupler_port: str = "left_pad",
coupler_offset: tuple[float, float] = (-45, 0),
probeline_coupler: ComponentSpec = coupler_straight,
probeline_coupling_gap: float = 16.0,
probeline_coupling_length: float | None = None,
) -> Component:
"""Returns a transmon qubit coupled to a quarter wave resonator and a probeline.
Uses a :func:`~qpdk.cells.waveguides.coupler_straight` to couple the
resonator to a probeline. The coupling section is inserted at the start
of the resonator meander, with one waveguide carrying the resonator signal
and the other providing ports for probeline routing.
Args:
qubit: Qubit component.
resonator: Resonator component.
resonator_meander_start: (x, y) position of the start of the resonator meander.
resonator_length: Length of the resonator in µm.
resonator_meanders: Number of meander sections for the resonator.
resonator_bend_spec: Specification for the bend component used in meanders.
resonator_cross_section: Cross-section specification for the resonator.
resonator_open_start: If True, adds an etch section at the start of the resonator.
resonator_open_end: If True, adds an etch section at the end of the resonator.
coupler: Coupler spec.
qubit_rotation: Rotation angle for the qubit in degrees.
coupler_port: Name of the qubit port to position the coupler relative to.
coupler_offset: (x, y) offset for the coupler position.
probeline_coupler: Component spec for the probeline coupling section.
probeline_coupling_gap: Gap between the resonator and probeline
waveguides in the coupling section in µm.
probeline_coupling_length: Length of the coupling section in µm.
"""
return _transmon_with_resonator_base(
qubit=qubit,
resonator=resonator,
resonator_meander_start=resonator_meander_start,
resonator_length=resonator_length,
resonator_meanders=resonator_meanders,
resonator_bend_spec=resonator_bend_spec,
resonator_cross_section=resonator_cross_section,
resonator_open_start=resonator_open_start,
resonator_open_end=resonator_open_end,
coupler=coupler,
qubit_rotation=qubit_rotation,
coupler_port=coupler_port,
coupler_offset=coupler_offset,
with_probeline=True,
probeline_coupler=probeline_coupler,
probeline_coupling_gap=probeline_coupling_gap,
probeline_coupling_length=probeline_coupling_length,
)
[docs]
@gf.cell
def transmon_with_resonator(
qubit: ComponentSpec = "double_pad_transmon_with_bbox",
resonator: ComponentSpec = partial(
resonator_quarter_wave_bend_start, length=4000, meanders=6
),
resonator_meander_start: tuple[float, float] = (-900, -1200),
resonator_length: float = 5000.0,
resonator_meanders: int = 5,
resonator_bend_spec: ComponentSpec = "bend_circular",
resonator_cross_section: CrossSectionSpec = "cpw",
resonator_open_start: bool = False,
resonator_open_end: bool = True,
coupler: ComponentSpec = partial(plate_capacitor_single, width=20, length=394),
qubit_rotation: float = 90,
coupler_port: str = "left_pad",
coupler_offset: tuple[float, float] = (-45, 0),
) -> Component:
"""Returns a transmon qubit coupled to a quarter wave resonator.
Args:
qubit: Qubit component.
resonator: Resonator component.
resonator_meander_start: (x, y) position of the start of the resonator meander.
resonator_length: Length of the resonator in µm.
resonator_meanders: Number of meander sections for the resonator.
resonator_bend_spec: Specification for the bend component used in meanders.
resonator_cross_section: Cross-section specification for the resonator.
resonator_open_start: If True, adds an etch section at the start of the resonator.
resonator_open_end: If True, adds an etch section at the end of the resonator.
coupler: Coupler spec.
qubit_rotation: Rotation angle for the qubit in degrees.
coupler_port: Name of the qubit port to position the coupler relative to.
coupler_offset: (x, y) offset for the coupler position.
"""
return _transmon_with_resonator_base(
qubit=qubit,
resonator=resonator,
resonator_meander_start=resonator_meander_start,
resonator_length=resonator_length,
resonator_meanders=resonator_meanders,
resonator_bend_spec=resonator_bend_spec,
resonator_cross_section=resonator_cross_section,
resonator_open_start=resonator_open_start,
resonator_open_end=resonator_open_end,
coupler=coupler,
qubit_rotation=qubit_rotation,
coupler_port=coupler_port,
coupler_offset=coupler_offset,
with_probeline=False,
)
# Create specific functions as partials of the general function
double_pad_transmon_with_resonator_and_probeline = partial(
transmon_with_resonator_and_probeline,
qubit="double_pad_transmon_with_bbox",
coupler=partial(plate_capacitor_single, width=20, length=394),
qubit_rotation=90,
coupler_port="left_pad",
coupler_offset=(-45, 0),
)
flipmon_with_resonator_and_probeline = partial(
transmon_with_resonator_and_probeline,
qubit="flipmon_with_bbox",
coupler=partial(plate_capacitor_single, width=10, length=58),
qubit_rotation=-90,
coupler_port="outer_ring_outside",
coupler_offset=(-10, 0),
)
double_pad_transmon_with_resonator = partial(
transmon_with_resonator,
qubit="double_pad_transmon_with_bbox",
coupler=partial(plate_capacitor_single, width=20, length=394),
qubit_rotation=90,
coupler_port="left_pad",
coupler_offset=(-45, 0),
)
flipmon_with_resonator = partial(
transmon_with_resonator,
qubit="flipmon_with_bbox",
coupler=partial(plate_capacitor_single, width=10, length=58),
qubit_rotation=-90,
coupler_port="outer_ring_outside",
coupler_offset=(-10, 0),
)
if __name__ == "__main__":
show_components(
transmon_with_resonator_and_probeline,
double_pad_transmon_with_resonator_and_probeline,
flipmon_with_resonator_and_probeline,
transmon_with_resonator,
double_pad_transmon_with_resonator,
flipmon_with_resonator,
)
