Quantum gates Definition and 14 Threads

Hello to everyone, I would like to ask you to brief questions. The first one is whether you could recommend any pedagogical books on Quantum Information and Computation. I tried Nielsen and Chuang but I found it too dense for a beginner in the field. The second question is the following: to...

Where do I start. I want to write the matrix form of a single or two qubit gate in the tensor product vector space of a many qubit system. Ill outline a simple example: Both qubits, ##q_0## and ##q_1## start in the ground state, ##|0 \rangle =\begin{pmatrix}1 \\ 0 \end{pmatrix}##. Then we...

I know |GHZ>=(1/sqrt(2))[1; 0; 0; 0; 0; 0; 0; 1], and |000>= the tensor product |0> x |0> x |0> = [1; 0; 0; 0; 0; 0; 0; 0]. Can I apply single qubit gates (i.e. 2x2 matrices) and CNOT (a 4x4 matrix) to 8x1 column vectors? If so, does anyone know a good starting point or a hint to get me moving...

I have numerous points of confusion: what does it mean that the matrices are within the exponential? How do I go about doing the matrix multiplication to prove the given form of CZ matches the common form, the 4x4 matrix? Update: using the fact that exp(At)=∑ ((t^n)/n!)*A^n, where A is a...

Am I correct in thinking that the system measures the probability |<f|1>|^2 for some state <f|? Then the probabilities for each of the six states would be: |<0|1>|^2= 0 |<1|1>|^2= 1 |<+x|1>|^2= |(1/√2)|^2 = 1/2 |<-x|1>|^2= |(-1/√2)|^2 = 1/2 |<+y|1>|^2= |(-i/√2)|^2 = 1/2 |<-y|1>|^2= |(i/√2)|^2...

In looking up "quantum gates", e.g. "Hadamard gate", all I come across is the matrix representations of the operations. But I do not see how, physically, they are achieved. (I also presume it will be different if we are talking about photons or electrons.) Could someone give me an appropriate...

Hi I am studying Quantum computing and basically have no understanding of quantum gates and my lecturer is not very helpful. I don't understand why a 4x4 quantum gate would ever effect a two qubit system because surely that is at best only a 2x2 matrix, assuming they effect each other through...

The example from my textbook shows one example of how to compute the matrix for a gate. The example is the U_CNOT operator: |00> -> |00>, |01> -> |01>; |10>->|11>; |11>->|10> Then they show that the operator is merely the sum of the outer products of these. |00><00| + |10><10| + |01><11| +...

I have lots of materials on the theory of quantum gates in terms of matrices, linear operators, and so forth. However, I would like to gain a basic understanding of how these matrices are achieved in practice. The difference is between knowing that a transistor acts as a switching or amplifying...

Hi everybody ... One of the one-qbit simple quantum gate is X which defined by: X: |0> ----- |1> |1> ----- |0> but how does this gate ( unitary operator ) act on |i> state? (i=0 or 1) I mean at first we have to measure what state is ( 0 or 1) and so flip them but after we know the...

After reading Seth Lloyd's book “Programming the Universe”(only once) I came up with a few questions. The way I understand it... He describes the fabric of space-time as consisting of an endless array of casual space (wires) and matter(quantum gates). The wires tell information where to go and...

How do quantum gates work and how our they different than classical gates?

I'm taking a course that requires me to come up with a research project. I'm officially in my sophomore year and I'm a Physics Major with a fairly broad exposure to electrical eng. and some advanced math courses. That being said... I'm very interested in computer simualtion of quantum...

Hi i am coding a quantum computer simulator. the simulator will be able to work in dimensions other than qubits. in other words the user can select either qubits(d=2), qutrits(d= 3)...etc Obviously in this scenario one must have the generalised versions of all the gates So far i have...