I suggest you follow https://www.cs.cmu.edu/~odonnell/quantum15/QuantumComputationScribeNotesByRyanODonnellAndJohnWright.pdf

Chapter Simulation and Design of Quantum Circuits

Yes, it is well known in quantum computing, we can implement all unitary operation on the quantum circuit. You can find details in any quantum computing book For example you can see "

Quantum Computation and Quantum Information" by Michael A. Nielsen .

Yes, it can be, and that's why quantum pc's are so powerful. Try do some research and make a good one.

Definitely, Try the link https://www.google.com/url?sa=t&rct=j&q=&esrc=s&source=web&cd=&ved=2ahUKEwj81fLA8sLtAhX3xzgGHWEKBi8QFjABegQIAxAC&url=http%3A%2F%2Fmmrc.amss.cas.cn%2Ftlb%2F201702%2FW020170224608149940643.pdf&usg=AOvVaw0J1VETo-IE3vff6z2niEuE

Dear Jency Rubia J :

These are called Quantum Circuits, since these circuits are made of Quantum Gates.

A Quantum Gate is an operation that you can do to the states of your Qubits.

So, if you have one Qubit in an specific state , lets say |0>

Then for example :

The NOT Gate (the quantum version of it) is a "bit flip" of your original state, then

This Gate is represented with the Pauli x matrix (sigma_x)

Then if you have you Quantum Bit in an original state |0> , and apply to it the NOT Gate (the Pauli x Matrix) , the result is a flip of 180° of the original state of your original Qubit in the Bloch Sphere , this is to say: |1>

Yes, we can.