Using the Resonator Dip Finder | Conductor Quantum

The Resonator Dip Finder detects resonator dips in 1D spectroscopy magnitude traces. It works with any input scale (dB, linear, or arbitrary units) through automatic normalization.

This model is useful during quantum device characterization when measuring resonator transmission to identify resonance frequencies. It accepts magnitude data from any scattering parameter measurement (e.g. S11, S21, S12, S22) and returns the indices of detected dips in the input data.

Installation

We recommend using pip, poetry, or uv to install the package.

$ pip install conductorquantum

Authentication

The SDK requires an API key for authentication. Sign in and create a new API key. Remember, your API key is your access secret - keep it safe with environment variables.

Using environment variables:

Python

1 from dotenv import load_dotenv
2 import os
3 from conductorquantum import ConductorQuantum
4 
5 # Load API key from .env file
6 load_dotenv()
7 TOKEN = os.getenv("CONDUCTOR_API_KEY")
8 
9 # Initialize client
10 client = ConductorQuantum(token=TOKEN)

Or provide the API key directly:

Python

1 from conductorquantum import ConductorQuantum
2 
3 # Initialize client with API key
4 client = ConductorQuantum(token="YOUR_API_KEY")

Input Format

The detector expects a 1D numpy array of shape (n,) where n ≥ 10:

Property	Value
Type	1D numpy array
Shape	`(n,)` where `n ≥ 10`
Values	Magnitude data in any scale (dB, linear, arbitrary units)

The model accepts magnitude data from any scattering parameter measurement (S11, S21, S12, S22, etc.). Input values must not contain NaN and must not be constant (all identical values).

Output Format

Key	Type	Description
`dip_indices`	`list[int]`	Indices into the input array where resonator dips were detected. Empty list if no dips are found.

Usage Example

You can download an example file to follow along with the example:

Python

1 from dotenv import load_dotenv
2 import os
3 import numpy as np
4 from conductorquantum import ConductorQuantum
5 
6 
7 # Load API key from .env file
8 load_dotenv()
9 TOKEN = os.getenv("CONDUCTOR_API_KEY")
10 
11 # Initialize client
12 client = ConductorQuantum(token=TOKEN)
13 
14 # Load spectroscopy magnitude data
15 data = np.load("resonator-dip-finder-v0.npy")  # shape (n,)
16 
17 # Detect resonator dips
18 result = client.models.execute(
19     model="resonator-dip-finder-v0",
20     data=data,
21 )
22 
23 # Access the detected dip indices
24 dip_indices = result.output["dip_indices"]
25 print(f"Detected {len(dip_indices)} dips at indices: {dip_indices}")

Output

1 Detected 3 dips at indices: [13, 68, 114]

Plotting the Results

Python

1 import matplotlib.pyplot as plt
2 
3 plt.figure(figsize=(10, 5))
4 plt.plot(data, 'k-', linewidth=0.8, label='Magnitude')
5 
6 for i, idx in enumerate(dip_indices):
7     if i == 0:
8         plt.axvline(x=idx, color='red', linestyle='--', alpha=0.7, label='Detected Dips')
9     else:
10         plt.axvline(x=idx, color='red', linestyle='--', alpha=0.7)
11 
12 plt.xlabel('Index')
13 plt.ylabel('Magnitude (a.u.)')
14 plt.title('Resonator Dip Finder v0')
15 plt.legend()
16 plt.grid(True, alpha=0.3)
17 plt.tight_layout()
18 plt.show()

Resonator Dip Finder v0 Output — Resonator Dip Finder v0 - detected dips marked with dashed red lines

Using Physical Units

To plot with real frequency values, map the indices back to your frequency axis:

Python

1 import matplotlib.pyplot as plt
2 import numpy as np
3 
4 # Your physical frequency axis
5 frequencies_ghz = np.linspace(6.8, 7.2, len(data))
6 
7 plt.figure(figsize=(10, 5))
8 plt.plot(frequencies_ghz, data, 'k-', linewidth=0.8, label='Magnitude')
9 
10 for i, idx in enumerate(dip_indices):
11     if i == 0:
12         plt.axvline(x=frequencies_ghz[idx], color='red', linestyle='--', alpha=0.7, label='Detected Dips')
13     else:
14         plt.axvline(x=frequencies_ghz[idx], color='red', linestyle='--', alpha=0.7)
15 
16 plt.xlabel('Frequency (GHz)')
17 plt.ylabel('Magnitude (a.u.)')
18 plt.title('Resonator Dip Finder v0')
19 plt.legend()
20 plt.grid(True, alpha=0.3)
21 plt.tight_layout()
22 plt.show()

Important Notes

The model accepts any scattering parameter measurement (S11, S21, S12, S22, etc.) - it is not specific to any single scattering parameter.
Works with any input scale: dB, linear, or arbitrary units.
No fixed input size is required - any 1D array with 10 or more data points is accepted.
Returns only dip indices, not frequencies. To convert indices to frequencies, map them back to your frequency axis.
Input data must not contain NaN values and must not be constant (all identical values).