## Top new questions this week:

### Is there any legitimate information about Microsoft quantum hardware?

I'm wondering if anyone has information regarding the current status of Microsoft quantum hardware? How many working qubits do they have? What are the gate depth/fidelity? Any details about ...

physical-realization

### Projective vs general measurements - a missing piece

This may be a very basic and common question (also discussed a lot), but strikingly enough I couldn't find the answer in the books or elsewhere. The projective measurement is given by the PVM on the ...

measurement

### Pauli Identity Using Tensor Network Notation

I am trying to understand the meaning of the equation shown in the above image taken from this paper, but I am unfamiliar with the tensor network notation. My current strategy is trying to write ...

mathematics tensor-networks
 answered by Renaud Vilmart 1 vote

### single-qubit gate followed by a single-qubit error

What are the ways to rewrite a single-qubit gate follow by a signle-qubit error?

quantum-state

### Quantum Entanglement : Changing states after measurement

Hi I am quite new to Quantum Mechanics and I came across with this confusion. Let's say there are 2 entangled particles A and B. 1. When A is measured to be state 0 (doesnt measure B) does it ...

entanglement

### Does quantum computers give any advantage over classical computers in sudoko?

To my basic knowledge I know that solving a generalized sudoko problems is an NP-complete problem so, is there any possible way quantum computers give an advantage over classical computers in this ...

algorithm quantum-information

### Moore's law for quantum computers

Moore's law states that performance of classical computers doubles every two years (later revised to 18 months) and a price for computing resources halves during same time period. Currently, it seems ...

ibm-q-experience resource-request physical-realization d-wave

## Greatest hits from previous weeks:

### What integers have been factored with Shor's algorithm?

Shor's algorithm is expected to enable us to factor integers far larger than could be feasibly done on modern classical computers. At current, only smaller integers have been factored. For example, ...

shors-algorithm

### Are there emulators for quantum computers?

Is there any way to emulate a quantum computer in my normal computer, so that I will be able to test and try quantum programming languages (such as Q#)? I mean something that I can really test my ...

emulation

### How to construct matrix of regular and "flipped" 2-qubit CNOT?

When constructing the matrices for the two CNOT based on the target and control qubit, I can use reasoning: "If $q_0$==$|0\rangle$, everything simply passes through", resulting in an Identity matrix ...

quantum-gate matrix-representation pauli-gates

### What exactly is an oracle?

What exactly is an "oracle"? Wikipedia says that an oracle is a "blackbox", but I'm not sure what that means. For example, in the Deutsch–Jozsa algorithm,$\hspace{85px}$,is the oracle just the box ...

quantum-information terminology oracles

### Classical complexity for Simon's problem

Simon's problem is that you are given a function $f : \{0,1\}^n \to \{0,1\}^n$ such that $f(x)=f(y)$ if and only if $x \bigoplus y$ is either $0^n$ or some unknown $s$. The problem is to find $s$. If ...

algorithm resource-request complexity-theory simons-algorithm

### Introductory material for quantum machine learning

In the past few days, I have been trying to collect material (mostly research papers) related to Quantum machine learning and its applications, for a summer project. Here are a few which I found ...

algorithm resource-request machine-learning

### Programming quantum computers for non-physics majors

I come from a non-physics background and I am very much interested in pursuing Quantum Computing - especially how to program them. Any guidance on how to get started will be very helpful.

resource-request programming

## Can you answer these questions?

### How to construct a multi-qubit controlled rotation with variable angle?

I'm trying to construct a circuit that performs the quantum transformation : Where $f$ is some function. Is there a way to do it without going through every possible value of $i$ ?

algorithm qiskit circuit-construction quantum-operation

### Generalized set of Pauli elements for a basis for the linear transformations on the vector space

I have been doing some practice problems from "Gentle introduction to Quantum Computing". I am a little bit lost with this one: Show that generalized set of Pauli elements for a basis for the linear ...

pauli-gates