## What do Pauli matrices represent?

Both phenomena use the Pauli matrices to represent the spin and orbital angular momentum magnetic interactions. The appropriate Hamiltonian operator is constructed using the Pauli matrices and its eigenvalues and eigenvectors are calculated, and the results interpreted.

## What is Pauli decomposition?

Pauli decomposition represents the measure of scattering in the Pauli basis, considering an orthogonal linear (H,V) basis (Liu et al. 2021). … Coherent and incoherent methods have their advantages and disadvantages.

**Are Pauli matrices orthogonal?**

Together with the identity matrix I (which is sometimes written as σ0), the Pauli matrices form an orthogonal basis, in the sense of Hilbert-Schmidt, for the real Hilbert space of 2 × 2 complex Hermitian matrices, or the complex Hilbert space of all 2 × 2 matrices.

**What are the different Pauli operator?**

The Pauli operators G = {I,X,Y,Z}, as already introduced in Chapter 2, can be represented in matrix form as follows: (7.1)

### Are Pauli matrices linearly independent?

Here, is the identity. We get four simultaneous equations in and it is fairly trivial to show that each must be zero. This implies that the four matrices are linearly independent and therefore form a basis for 2×2 matrices.

### Is the Pauli group Abelian?

For the three Pauli matrices, {σ1,σ2=0}, so certainly this can not form an abelian group. The Pauli group is an isomorphism with D4. The elements of the Pauli group are {I,σx,σy,iσz,−I,−σx,−σy,−iσz}, so the order of this group is 8.

**How many Clifford gates are there?**

The Clifford group is generated by three gates, Hadamard, S and CNOT gates. Since all Pauli matrices can be constructed from the phase S and Hadamard gates, each Pauli gate is also trivially an element of the Clifford group.

**What is a non Clifford gate?**

There are two groups of quantum gates – Clifford gates and non-Clifford gates. Representatives of Clifford gates are Pauli matrices I, X, Y and Z, Hadamard gate H, S gate and CNOT gate. Non-Clifford gate is for example T gate and Toffoli gate (because its implementation comprise T gates).

## Is hadamard a Clifford?

No, the controlled Hadamard isn’t a Clifford operation. An operation is Clifford if it conjugates Pauli products into Pauli products.