3 ms·
Not an expert, but I can answer some of your questions at least. > Thus this mean that "particles" can be entangled, not only to one "particle", but to many at
by sebzim4500 4y ago
Not an expert, but I can answer some of your questions at least.
> Thus this mean that "particles" can be entangled, not only to one "particle", but to many at the same time? Or are they entangled in series or something?
There is in principle no limit to how many particles can be entangled together, but in practice it becomes harder and harder to prevent any particles from interacting with the external environment.
You have to be careful with terms here, because of the 'Monogamy of Entanglement', which essentially says that if A is fully entangled with B then B cannot be fully entangled with C.
https://en.wikipedia.org/wiki/Monogamy_of_entanglement https://en.wikipedia.org/wiki/Monogamy_of_entanglement
So how does this not contradict my earlier statement? When three particles are fully mutually entangled then any pair of them in isolation are not entangled at all.
To be more concrete, if you have three qbits which are in a superposition of 000 and 111, then no experiment you can do on the first two qbits can possibly distinguish this from two classically correlated bits unless you allow the third qbit to be involved in the experiment.
>As I understand QC you dont get a absolute answer, just a probability it is the right answer. And because of this you have to run the "simulation" many times to verify the answer. As I also understand is that when you read out the state of an qubit the quantum state collapse and so does it do for all the other qubits.
It's true that all the qbits collapse, but the state that they collapse is still interesting. You can get much more than 1 bit of useful information per simulation.
> How many times must you actually run a simulation in a QC to get an answer?
Depends on both the algorithm and the details of the hardware. Assuming an 'ideal' quantum computer (which will probably never exist), Grover's algorithm will give you the right answer after 2 runs on average.