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Does this experimental discovery of anyons enables the topological quantum computer (e.g. Microsoft) to become a reality?
Microsoft has its own agenda regarding quantum computer - it is topological quantum computer being invented by the team lead by Michael Freedman https://www.microsoft.com/en-us/research/project/topological-quantum-computing/
While this idea is very…
TomR
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Is the Haar measure invariant under conjugation?
Denote the Haar measure on the unitary group $U(\mathcal X)$ by $\eta$. Does this equation hold (assuming the integral exists):
$$\int d\eta(U) f(U) = \int d\eta(U) f(U^\dagger)$$
Intuitively this makes sense because choosing a random $U$ seems to…
dmitryk
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7
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Why isn't NV-center-based quantum computing mainstream?
One can rattle off names of implementations of Superconducting Qubits, transmon qubits, etc
For example, see Physical realizations used by Google
But NV centre Qubits as in this question, Is there any company that backs and implements diamond…
Tejas Shetty
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7
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How to add several parameters in qiskit circuit?
I want to construct an ansatz circuit in Qiskit, so I need some parameters to act on the gates (e.g. RX(a), RY(b)). In the Qiskit tutorials I find a way to implement a parameter:
import numpy as np
theta_range = np.linspace(0, 2 * np.pi,…
wu Peter
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7
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What are some current applications of Quantum Computing in drug discovery? Are there any test examples of this?
I am interested in applying the power of Quantum Computing to drug discovery. Although I realize that quantum computing is limited in regards to modeling drug-like compounds and their interactions right now, I was curious as to any useful resources…
Rob James
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7
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Hadamard Test to calculate imaginary part
I am trying to understand the Hadamard Test by finding the average value of $U_1$, which is a diagonal matrix with $1$ everywhere except on the first element.
I performed the regular Hadamard Test as presented in the wiki page:
and so far so good,…
César Leonardo Clemente López
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7
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Adding a phase to qubit: why is it necessary for arbitrary single qubit gate
By convention, we often write a single qubit gate as:
$$U=e^{i \alpha} R_z(\beta) R_y(\gamma) R_z(\delta)$$
We notice that in addition to the three rotations, there is a coefficient $e^{i \alpha}$. What disturbs me is that this extra phase $e^{i…
Marco Fellous-Asiani
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7
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What's the observable when measuring multiple qubits in the computational basis?
In Nielsen and Chuang (Quantum Computing and Quantum Information) the following definition is given to a projective measurement:
Projective measurements are described by an observable $M$:
$$M = \sum_m m P_m$$
with $P_m$ a projector onto the…
nathan raynal
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Does Barkhausen noise affect the measurement of magnetic particle based qubits?
Q1: I've tried to find out if Barkhausen noise affects the measurement of spin-wave excitations in magnetic particle material based qubits.
I prefer implementations such as those described in "Magnetic qubits as hardware for quantum computers",…
Rob
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Would IBM's "compiler" turn my identity circuit into nothing?
If I were to create a circuit with the following gate:
$$\tag{1}R_\phi = \begin{bmatrix} 1 & 0 \\ 0 & e^{i \phi} \end{bmatrix},$$
with $\phi$ specified to be equal to 0, then the gate that I am running is just the identity gate, and the circuit is…
user1271772 No more free time
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7
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Why can I use the Sum of Eigenvectors for Phase Estimation in Shor
In phase estimation, we start by using an eigenvector $\newcommand{\ket}[1]{\lvert#1\rangle}\ket u$ to find the corresponding eigenvalue lambda. So far so good. In the order finding algorithm, we also use phase estimation to find the eigenvalues for…
rhundt
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Improving probability of spontaneous parametric down conversion
As mentioned in an earlier question of mine, I am interested in using type one spontaneous down conversion (SPDC) in optical quantum computing. However, SPDC is a somewhat low probability occurrence - most of the photons pass straight through the…
auden
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How do I check if a gate represented by Unitary $U$ is a Clifford Gate?
The Gottesman–Knill theorem states that stabilizer circuits, circuits that only consist of gates from Clifford group, can be perfectly simulated in polynomial time on a probabilistic classical computer. Clifford Gates are hence extremely useful in…
vasjain
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How can the Holevo bound be used to show that $n$ qubits cannot transmit more than $n$ classical bits?
The inequality $\chi \le H(X)$ gives the upper bound on accessible information.
This much is clear to me. However, what isn't clear is how this tells me I cannot transmit more than $n$ bits of information.
I understand that if $\chi < H(X)$, then…
GaussStrife
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How can we implement controlled-T gate using CNOT and H, S and T gates?
In general, is there any way to implement a controlled version of an arbitrary gate U if we are given only CNOT and U gate?
Rabins Wosti
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