Semiconductor Si Spin Qubit Decoherence T2 Calculator
Extract actual Si-spin echo exponential T2 with independently normalized envelope, not Ramsey T2*, spin diffusion spatial length, arbitrary stretched exponent or readiness.
Description
An exponential spin-echo envelope gives an apparent T₂ when fitted in logarithmic response space.
An exponential spin-echo envelope gives an apparent T₂ when fitted in logarithmic response space.1
That fit is distinct from a Ramsey T₂* estimate or a stretched-exponential model.
When to use Semiconductor Si Spin Qubit Decoherence T2 Calculator
Use this tool when you need to fit an apparent exponential decay length or time. Prepare measured device or specimen records under independently matched branch, temperature, frame, and unit conventions.
How to use Semiconductor Si Spin Qubit Decoherence T2 Calculator and understand its results
- Prepare measured device or specimen records under independently matched branch, temperature, frame, and unit conventions.
- Enter observedEchoTimesSeconds, observedNormalizedEchoEnvelope, following the field table and rules below, then run the tool.
- Read fittedSpinEchoT2Seconds, echoFitRSquared. Use the output meanings below to interpret units, signs, flags, and any nested result fields.
- Correct reported input issues and run again. For a successful result, check the stated evidence coverage and assumptions before using it in your review.
| Input field | Meaning | Value type | Requirement |
|---|---|---|---|
| observedEchoTimesSeconds | Observed echo times seconds | list of number | Required |
| observedNormalizedEchoEnvelope | Observed normalized echo envelope | list of number | Required |
Use at least two aligned coordinates and strictly positive signal values with nonzero coordinate variance. Fit the natural logarithm of signal against coordinate by ordinary least squares with a free intercept. Require a negative fitted slope; nondecaying fitted traces are rejected. Return the negative reciprocal of slope and the log-domain R². Coordinates need not be sorted, and an individually increasing sample can be accepted if the fitted trend is negative.
ln(signal)=a+b×coordinate; decayLengthOrTime=−1/b, b<0 Symbols follow the input and output meanings and the calculation rules above.
Echo times must be nonnegative seconds and normalized envelopes must be greater than zero and at most one. The result is a time in seconds.
| Output field | Meaning | Value type |
|---|---|---|
| fittedSpinEchoT2Seconds | Fitted spin echo t2 seconds | number |
| echoFitRSquared | Echo fit R² | number |
{
"input": {
"observedEchoTimesSeconds": [
0,
1,
2
],
"observedNormalizedEchoEnvelope": [
1,
0.5,
0.25
]
},
"output": {
"fittedSpinEchoT2Seconds": 1.4426950408889634,
"echoFitRSquared": 1
}
}Limitations and assumptions
An exponential model and selected measurement branch must be justified independently. R² summarizes a log-domain fit; it is not a confidence interval, full physical model, or device readiness check.
Missing required fields, unknown fields, wrong types, and violated calculation rules are input issues. Numeric values must be finite; nonfinite results are rejected. Evidence arrays must be dense, with no missing cells. Numeric observation lists allow at most 10,000 entries, subject to any smaller bounds stated above.
Alternative or Complementary methods
For a related review, use Semiconductor Spintronic Spin Diffusion Length Calculator: An exponential spatial spin-signal decay can be fitted in logarithmic response space. The reciprocal negative slope defines an apparent spin diffusion length. For a complementary step, use Semiconductor Transmon Anharmonicity Calculator: Anharmonicity compares adjacent transition frequencies. Subtracting measured f01 from f12 retains the sign and expresses the mismatch relative to f01.
References
Similar or alternative tools
- Semiconductor Spintronic Spin Diffusion Length Calculator
An exponential spatial spin-signal decay can be fitted in logarithmic response space. The reciprocal negative slope defines an apparent spin diffusion length.
- Semiconductor Transmon Anharmonicity Calculator
Anharmonicity compares adjacent transition frequencies. Subtracting measured f01 from f12 retains the sign and expresses the mismatch relative to f01.