17 Why can the Discrete Fourier Transform be implemented efficiently as a quantum circuit? 2018-05-03T19:38:39.930

15 Why does the "Phase Kickback" mechanism work in the Quantum phase estimation algorithm? 2018-07-01T19:47:46.293

12 How does Fourier sampling actually work (and solve the parity problem)? 2018-03-17T06:30:57.343

9 Simplified explanation of Shor/QFT transformation as thumbtack 2018-07-04T14:02:39.323

9 Quantum Algorithms for Convolution 2018-08-08T01:55:53.730

9 Does the quantum Fourier transform have many applications beyond period finding? 2020-02-13T04:14:58.097

8 Shor's algorithm weaknesses & uniqueness of close rational 2018-11-14T08:07:22.847

8 Why is quantum Fourier transform required in Shor's algorithm? 2019-02-07T04:42:52.393

7 Shor's algorithm: initialization of second register 2020-11-17T16:54:42.150

6 Weak Fourier Sampling vs Strong Fourier Sampling? 2018-10-15T21:30:59.623

6 How to describe, or encode, the input vector x of Quantum Fourier Transform? 2018-11-20T09:25:26.387

6 What happens with first phase factor in QFT? 2019-01-27T11:26:13.907

6 Is the quantum Fourier transform efficient if only one control-phase is allowed in the gate set 2019-06-16T15:53:32.987

6 Why can the QFT be replaced by Hadamard gates? 2020-02-07T08:57:07.497

5 Simplifying Quantum Tensor products with coefficients 2018-08-14T20:22:19.970

5 Implementation of inverse QFT? 2018-12-05T21:57:07.493

5 Quantum Fourier Transform without SWAPs 2019-06-10T21:00:34.877

5 Does the Quantum Fourier Transform (QFT) preserve entanglement? 2020-02-19T16:15:33.640

5 Question Regarding Quantum Period-Finding Fourier Transform Approximation 2020-05-05T01:52:19.353

5 Why can I not apply a control gate/function to a gate like T, S, S dagger, ... (using IBM Quantum Experience)? Is there another option? 2021-01-19T12:08:17.940

4 Example of Quantum Fourier Computation for three qubits 2018-05-31T14:36:20.190

4 Do the probability amplitudes of the superposition state produced by the QFT transform convey useful information? 2018-10-17T08:52:23.567

4 Why does Fourier sampling allow to efficiently recover hidden subgroups? 2018-10-18T15:28:58.990

4 Why do we use the quantum superposition for a period instead of factors in Shor's algorithm? 2019-02-16T13:39:32.073

4 Phase estimation error analysis 2019-05-21T16:43:13.793

4 Why should we use inverse QFT instead of QFT in Shor's algorithm? 2019-06-09T06:42:05.890

4 Hidden subgroup problem 2019-07-27T14:52:12.450

4 How to find a circuit for the roots of QFT? 2020-06-20T04:08:56.750

4 How to write a classical version of Shor's algorithm 2020-10-19T16:35:21.587

4 Quantum Fourier Transform for general cyclic groups 2020-11-09T15:34:58.790

4 What is the matrix for a SWAP operation on two qubits? 2020-12-13T18:49:59.063

3 2-qubit QFT in IBMQ: controlled phase rotation 2019-06-03T20:06:33.123

3 Secret sharing though quantum operations 2019-11-05T13:33:28.177

3 Cannot replicate results in article on pricing financial derivatives on IBM Q 2020-01-02T09:46:24.800

3 What is the probability to get all qubits equal zero after QFT 2020-03-28T16:04:02.983

3 How to implement exponentiation of a gate without breaking complexity? 2020-04-05T16:09:05.260

3 How to check if a quantum circuit is deterministic? 2020-04-22T23:32:01.600

3 Are there any common applications where one can replace FFT with Quantum Fourier Transform? 2020-07-25T12:53:08.043

3 Intuitively, what does the quantum Fourier transform do? 2020-07-30T16:38:35.170

3 Abelian Hidden Subgroup Problem for arbitrary cyclic p-Groups 2020-10-26T00:15:47.500

3 Qiskit Inverse of a quantum fourier transformation 2020-11-15T17:04:35.770

3 Shor's algorithm: what to do after reading the QFT's result twice? 2020-12-05T16:37:41.727

3 Measuring in the computational basis in the single qubit gate QFT implementation 2020-12-08T21:28:08.163

3 How does the QFT represent the frequency domain? 2020-12-27T03:21:01.047

3 Application of QFT to Order-finding 2021-01-12T12:51:25.223

3 Show that Quantum Fourier Transform maps Bell states to Bell states 2021-01-13T10:00:38.467

3 Efficient QFT-based QPEA complexity 2021-02-03T15:24:13.307

2 Using Quantum Fourier Transform in adding two 2-bit numbers 2019-06-26T15:06:23.697

2 How to decompose the Quantum Fourier Inverse matrix into elementary quantum gates? 2019-07-12T18:55:33.530

2 The control phase gate in Quantum fourier transform and the question it brings up regarding control gates in general 2019-08-15T02:03:42.237

2 How do I prove that $\sum_{y=0}^{N-1}e^{2\pi i xy/N}=N\delta_{x,0}$? 2019-09-01T04:00:15.160

2 Implementing QFT for Shor's Algorithm 2019-11-19T00:28:16.723

2 What does "decoherence attenuates the density matrix" mean? 2020-02-28T21:52:36.830

2 Quantum computers don't try all the possible solutions, so how does the QFT really work? 2020-04-12T17:51:18.580

2 Proof of QFT for a Periodic Function 2020-06-09T15:59:18.517

2 Indexing an "unknown" quantum state 2020-06-19T12:00:18.813

2 QFT on timeseries Data and compare results with classical FFT 2020-07-01T07:11:32.067

2 Why after transpiling a Qiskit circuit we obtain a different result? 2020-07-09T15:01:00.753

2 N-Qubit Hadamard vs Quantum Fourier Transform 2020-07-21T23:34:29.037

2 Prove that QFT and Walsh-Hadamard gates give the same output when acting on $\lvert x\rangle\lvert 0\rangle$ 2020-07-29T00:40:49.723

2 How to apply QFT to a quantum state in superposition? 2020-08-02T15:55:34.500

2 Constructing arbitrary functions for the Abelian HSP 2020-09-25T23:35:51.503

2 A simple question about QFT and CNOT 2020-12-20T03:41:24.310

2 Lieb-Robinson Bound in 2nd quantized description? 2021-01-22T12:32:29.330

2 Intuition behind the use of inverse FFT in Quantum Circuit for Hamming weight 2021-02-27T01:17:21.557

1 Quantum Fourier Transform on two qubits: Non orthogonal outputs 2018-09-17T13:42:11.780

1 Why are these circuits not producing the expected output? 2018-12-05T20:35:36.717

1 Why are these circuits not producing the same output? 2018-12-06T00:21:42.003

1 Quantum transformation equivalent to Discrete Wavelet transform 2019-04-08T07:53:02.563

1 What is the intuition of using Hadamard gate in quantum fourier transform? 2019-06-25T04:27:57.937

1 What is the cost of implementing the Quantum Fourier transform in a classical computer? 2019-10-04T22:59:44.357

1 Unable to recognise little-endian format 2019-10-05T08:08:35.003

1 Can a QFT be implemented as a physical change of the measurement basis? 2019-11-15T19:28:58.137

1 Is it possible to demonstrate a quadratic speed-up of a quantum algorithm on a classical computer? 2020-03-02T14:31:20.663

1 qiskit: IQFT acting on subsystem of reversed-ordered qubits state 2020-03-13T14:30:41.523

1 How does Inverse QFT work in Quantum Phase Estimation? 2020-04-18T06:49:13.567

1 QFT of 3-bit system 2020-05-25T16:29:20.627

1 Is there a quantum operation to change a phase $e^{(0.q_0 q_1 q_2 q_3)}$ into $e^{(0.q_1 q_2 q_3)}$? 2020-06-24T08:40:36.213

1 Trying to perform Quantum Phase Estimation on T-gate 2020-12-13T23:17:00.007

1 Calculating the QFFT according to Coppersmith 2021-02-27T22:14:41.533

0 How to obtain the density matrix using tomography in the real device? 2020-06-01T17:33:47.773

0 Quantum circuit, Fourier Transform/Decomposition? 2020-10-04T02:24:46.653

0 What is this equation for coin operator is trying to do in this quantum walk for Non-regular graph? This coin operator is called Fourier coin 2020-11-21T09:48:47.317

0 Qubit ordering in qiskit 2021-01-12T10:59:59.753