Questions tagged [arithmetic]
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11
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3
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On unitary matrix form suggested in the Elementary gates paper
In the Elementary gates for quantum computation paper by Barenco et al authors start their proofs by defining a generic form of 2x2 unitary matrix of $\mathbb{C}$ as follows:
Can you help me with the ...
- 133
0
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1
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31
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Qiskit: RGQFTMultiplier is giving wrong answers for 28 bits number multiplication with MPS simulator
I am using RGQFTMultiplier for multiplying two unsigned integers. Starting from simpler example of 2 qbits input, I reached 24 and all worked fine. I am using MPS as backend and my RAM is 32. However ...
- 223
2
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1
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43
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Comparing qubit values in pairs of qubits
For $2N$ qubits $\{i_1,j_1\ldots i_N,j_N\}$ I would like to have a circuit changing the value of an ancillary register from $0$ to $1$ if $i_1=j_1$ AND $i_2=j_2$ AND ... AND $i_N=j_N$.
One way to ...
- 1,830
1
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2
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Problem adding two numbers in a quantum computer with Drapper's algorithm
I would like to add numbers. In this simple example a = 1 and b = 1.
The circuit I created looks like this:
We have two registers a and b. Both have a size of 3 qubits. I'm using Big Endian notation, ...
- 47
0
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1
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192
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Why a Fourier Adder Gives Multiple Faulty Results?
I followed this tutorial and wrote a code that implements the following circuit:
By writing the following code:
...
1
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1
answer
180
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Is it possible to implement an in-place multiplication quantum circuit?
How can a reversible multiplication quantum circuit be implemented? By "reversible" I mean one that performs a *= b on the inputs a and b of the ...
- 31
2
votes
1
answer
118
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Oracle for amplitude addition
Assume one is given two oracle circuits providing access to matrices $A_{ij}$ and $B_{ij}$ as follows (see eq. (6.2) here):
\begin{equation}
O_A |0\rangle|i\rangle|j\rangle=\left(A_{ij}|0\rangle+\sqrt{...
- 1,830
2
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1
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60
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How can one sort two registers without leaving an entangled ancilla behind used for comparison?
If we have an state $\alpha|abc\rangle + \beta|bad\rangle$, and we know that $a<b$, how can we obtain state $\alpha|abc\rangle + \beta|abd\rangle$ without entangled ancillas, if we don't know $c$ ...
- 491
3
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1
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79
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How to verify a matrix-vector product with Grover search?
I am looking at the Ambainis et al. method of verifying whether $AB = C$ in $O(n^{7/4})$ queries, as described in Buhrman and Špalek. They have the following sentence:
verify the matrix-vector ...
- 135
2
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1
answer
76
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Formulate Controlled-Not as mapping (including modulo-2 addition)
We often see that the controlled-not gate is written as
$CNOT |x y \rangle = |x\rangle |x \oplus y\rangle$.
Now, would it be possible to further expand this to get a general equation?
$$(\alpha_0 |0\...
- 35
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4
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505
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Computing $e^x$ on a quantum computer
Does anyone know how to make a quantum circuit to compute exponentials where the exponent can be a fraction? To be more precise, I'm looking for a fixed point quantum arithmetic circuit that does the ...
- 1,654