QubimiQuantum ideas made visible
058 min

QFT is not a faster FFT

Contrast a readable classical spectrum with a quantum state transform.

05

Correct the common misconception that QFT simply replaces FFT.

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01 · Set up the comparison

Choose a workload and scale

Correct the common misconception that QFT simply replaces FFT.

1

Workloads

Choose what kind of work to test

Workload is what the machine does; scale is how much. Choosing one loads a starting scale.

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2

Signal size

12

Scaling: Readable audio spectrumCustom scale
Short signalLong signal

Changing the scale keeps this workload. Choose another card above to change workloads.

3

Test question

What can FFT read directly that one QFT measurement cannot?

Current setupReadable audio spectrumSignal size: 12

02 · Compare

Result snapshot

Choose a workload and scale, then run the comparison to see the best fit and evidence.

Choose a workload and scale, then run the comparison to see the best fit and evidence.

03

Explain

Explain

FFT returns an accessible frequency array. QFT transforms amplitudes inside a quantum state, and measurement cannot read the full array directly.

04

Challenge

Identify a result available from FFT but not from one QFT measurement.

Correct the common misconception that QFT simply replaces FFT.