from dataclasses import dataclass
import numpy as np
import plotly.graph_objects as go
from plotly.subplots import make_subplots
from ...auto.operation import Parameters
from ..utils import HZ_TO_GHZ
[docs]
@dataclass(kw_only=True)
class FluxFrequencySweepParameters(Parameters):
"""Parameters to define flux DC sweep."""
freq_width: int
"""Width for frequency sweep relative to the readout frequency [Hz]."""
freq_step: int
"""Frequency step for sweep [Hz]."""
bias_width: float
"""Width for bias sweep [V]."""
bias_step: float
"""Bias step for sweep [V]."""
@property
def frequency_range(self) -> np.ndarray:
return np.arange(-self.freq_width / 2, self.freq_width / 2, self.freq_step)
@property
def bias_range(self) -> np.ndarray:
return np.arange(-self.bias_width / 2, self.bias_width / 2, self.bias_step)
[docs]
def create_data_array(freq, bias, signal, dtype):
"""Create custom dtype array for acquired data."""
size = len(freq) * len(bias)
ar = np.empty(size, dtype=dtype)
frequency, biases = np.meshgrid(freq, bias)
ar["freq"] = frequency.ravel()
ar["bias"] = biases.ravel()
ar["signal"] = signal.ravel()
return np.rec.array(ar)
[docs]
def flux_dependence_plot(data, fit, qubit, fit_function=None):
figures = []
qubit_data = data[qubit]
frequencies = qubit_data.freq * HZ_TO_GHZ
filtered_freq, filtered_bias = data.filtered_data(qubit)
fig = go.Figure()
fig.add_trace(
go.Heatmap(
x=qubit_data.freq * HZ_TO_GHZ,
y=qubit_data.bias,
z=qubit_data.signal,
colorbar=dict(title="Signal [a.u.]"),
colorscale="Viridis",
),
)
fig.add_trace(
go.Scatter(
x=filtered_freq * HZ_TO_GHZ,
y=filtered_bias,
name="Estimated points",
mode="markers",
marker=dict(color="rgb(248, 248, 248)"),
)
)
# TODO: This fit is for frequency, can it be reused here, do we even want the fit ?
if (
fit is not None
and fit_function is not None
and not data.__class__.__name__ == "CouplerSpectroscopyData"
and qubit in fit.fitted_parameters
):
params = fit.fitted_parameters[qubit]
bias = np.unique(qubit_data.bias)
fig.add_trace(
go.Scatter(
x=fit_function(bias, **params),
y=bias,
showlegend=True,
name="Fit",
marker=dict(color="rgb(248, 248, 248)"),
),
)
fig.add_trace(
go.Scatter(
x=[
fit.frequency[qubit] * HZ_TO_GHZ,
],
y=[
fit.sweetspot[qubit],
],
mode="markers",
marker=dict(
size=8,
color="red",
),
name="Sweetspot",
showlegend=True,
),
)
fig.update_xaxes(
title_text="Frequency [GHz]",
)
fig.update_yaxes(title_text="Bias [V]")
fig.update_layout(xaxis1=dict(range=[np.min(frequencies), np.max(frequencies)]))
fig.update_layout(
showlegend=True,
legend=dict(orientation="h"),
)
figures.append(fig)
return figures
[docs]
def flux_crosstalk_plot(data, qubit, fit, fit_function):
figures = []
fitting_report = ""
all_qubit_data = {
index: data_qubit
for index, data_qubit in data.data.items()
if index[0] == qubit
}
fig = make_subplots(
rows=1,
cols=len(all_qubit_data),
horizontal_spacing=0.3 / len(all_qubit_data),
vertical_spacing=0.1,
subplot_titles=len(all_qubit_data) * ("Signal [a.u.]",),
)
for col, (flux_qubit, qubit_data) in enumerate(all_qubit_data.items()):
frequencies = qubit_data.freq * HZ_TO_GHZ
fig.add_trace(
go.Heatmap(
x=frequencies,
y=qubit_data.bias,
z=qubit_data.signal,
showscale=False,
),
row=1,
col=col + 1,
)
if fit is not None:
if flux_qubit[1] != qubit and flux_qubit in fit.fitted_parameters:
fig.add_trace(
go.Scatter(
x=fit_function(
xj=qubit_data.bias, **fit.fitted_parameters[flux_qubit]
),
y=qubit_data.bias,
showlegend=not any(
isinstance(trace, go.Scatter) for trace in fig.data
),
legendgroup="Fit",
name="Fit",
marker=dict(color="green"),
),
row=1,
col=col + 1,
)
fig.update_xaxes(
title_text="Frequency [GHz]",
row=1,
col=col + 1,
)
fig.update_yaxes(
title_text=f"Qubit {flux_qubit[1]}: Bias [V]", row=1, col=col + 1
)
fig.update_layout(xaxis1=dict(range=[np.min(frequencies), np.max(frequencies)]))
fig.update_layout(xaxis2=dict(range=[np.min(frequencies), np.max(frequencies)]))
fig.update_layout(xaxis3=dict(range=[np.min(frequencies), np.max(frequencies)]))
fig.update_layout(
showlegend=True,
)
figures.append(fig)
return figures, fitting_report
[docs]
def G_f_d(xi, xj, offset, d, crosstalk_element, normalization):
"""Auxiliary function to calculate qubit frequency as a function of bias.
It also determines the flux dependence of :math:`E_J`,:math:`E_J(\\phi)=E_J(0)G_f_d`.
For more details see: https://arxiv.org/pdf/cond-mat/0703002.pdf
Args:
xi (float): bias of target qubit
xj (float): bias of neighbor qubit
offset (float): phase_offset [V].
d (float): asymmetry between the two junctions of the transmon.
Typically denoted as :math:`d`. :math:`d = (E_J^1 - E_J^2) / (E_J^1 + E_J^2)`.
crosstalk_element(float): off-diagonal crosstalk matrix element
normalization(float): diagonal crosstalk matrix element
Returns:
(float)
"""
return (
d**2
+ (1 - d**2)
* np.cos(
np.pi
* (xi * normalization + normalization * xj * crosstalk_element + offset)
)
** 2
) ** 0.25
[docs]
def transmon_frequency(
xi, xj, w_max, d, normalization, offset, crosstalk_element, charging_energy
):
r"""Approximation to transmon frequency.
The formula holds in the transmon regime Ej / Ec >> 1.
See https://arxiv.org/pdf/cond-mat/0703002.pdf for the complete formula.
Args:
xi (float): bias of target qubit
xj (float): bias of neighbor qubit
w_max (float): maximum frequency :math:`w_{max} = \sqrt{8 E_j E_c}
d (float): asymmetry between the two junctions of the transmon.
Typically denoted as :math:`d`. :math:`d = (E_J^1 - E_J^2) / (E_J^1 + E_J^2)`.
normalization(float): diagonal crosstalk matrix element
offset (float): phase_offset [V].
crosstalk_element(float): off-diagonal crosstalk matrix element
charging_energy (float): Ec / h (GHz)
Returns:
(float): qubit frequency as a function of bias.
"""
return (w_max + charging_energy) * G_f_d(
xi,
xj,
offset=offset,
d=d,
normalization=normalization,
crosstalk_element=crosstalk_element,
) - charging_energy
[docs]
def transmon_readout_frequency(
xi,
xj,
w_max,
d,
normalization,
crosstalk_element,
offset,
resonator_freq,
g,
charging_energy,
):
r"""Approximation to flux dependent resonator frequency.
The formula holds in the transmon regime Ej / Ec >> 1.
See https://arxiv.org/pdf/cond-mat/0703002.pdf for the complete formula.
Args:
xi (float): bias of target qubit
xj (float): bias of neighbor qubit
w_max (float): maximum frequency :math:`w_{max} = \sqrt{8 E_j E_c}
d (float): asymmetry between the two junctions of the transmon.
Typically denoted as :math:`d`. :math:`d = (E_J^1 - E_J^2) / (E_J^1 + E_J^2)`.
normalization(float): diagonal crosstalk matrix element
offset (float): phase_offset [V].
crosstalk_element(float): off-diagonal crosstalk matrix element
resonator_freq (float): bare resonator frequency [GHz]
g (float): readout coupling.
charging_energy (float): Ec / h (GHz)
Returns:
(float): resonator frequency as a function of bias.
"""
qubit_frequency = transmon_frequency(
xi=xi,
xj=xj,
w_max=w_max,
d=d,
normalization=normalization,
offset=offset,
crosstalk_element=crosstalk_element,
charging_energy=charging_energy,
)
return resonator_freq + g**2 * (
1 / (resonator_freq - qubit_frequency)
- 1 / (resonator_freq - qubit_frequency + charging_energy)
)
[docs]
def qubit_flux_dependence_fit_bounds(qubit_frequency: float):
"""Returns bounds for qubit flux fit."""
return (
[
qubit_frequency * HZ_TO_GHZ - 1,
0,
-1,
],
[
qubit_frequency * HZ_TO_GHZ + 1,
np.inf,
1,
],
)