2,520 reputation
1117
bio website
location
age
visits member for 4 years
seen 2 hours ago

2h
comment Quantum entanglement thought experiment
@suissidle As long as you measure the spin in a single fixed direction (e.g. up/down), it is coin logic, and it does indeed miss the point of QM. You might want to read up on Bell inequalities or the CHSH inequality. You should find references e.g. here on physics.se or on Wikipedia.
3h
answered Quantum entanglement thought experiment
3h
comment How to produce a given entangled state of two quantum bits?
What exactly is your question?
5h
revised Why can't it work? Perpetual motion machine
added 2 characters in body
5h
revised Why can't it work? Perpetual motion machine
added 2 characters in body
5h
revised Why can't it work? Perpetual motion machine
added 348 characters in body
5h
answered Why can't it work? Perpetual motion machine
6h
reviewed No Action Needed Would a fast moving (approaching $c$) stream of particles be affected by the gravitational pull of a gas giant?
6h
reviewed Approve Why doesn't light kill me?
7h
revised Relationship between Toffoli gate and Deutsch gate
edited body
8h
comment Relationship between Toffoli gate and Deutsch gate
I have now posted it as an answer, in case you want to accept it.
8h
answered Relationship between Toffoli gate and Deutsch gate
11h
comment Relationship between Toffoli gate and Deutsch gate
$R(\theta)$ is not the phase shift operation (though it is stated in your quote), it should rather be a rotation around the $X$ axis, as e.g. stated on Wikipedia, en.wikipedia.org/wiki/Quantum_gate#Universal_quantum_gates. Using the formula given there, it should be clear why the Toffoli gate is obtained for $\theta=\pi/2$. (Note that if $R$ were a phase shift, the Deutsch gate would be not universal, as it would be a diagonal operation!)
13h
reviewed Reject Why doesn't the Moon fall upon Earth?
14h
revised Relationship between Toffoli gate and Deutsch gate
edited tags
14h
reviewed No Action Needed Can anyone tell me the name of this constant?
14h
comment Relationship between Toffoli gate and Deutsch gate
What is $R(\theta)$? -- And did you try to write a matrix representation of the Deutsch gate? What did you get? Where did you get stuck?
16h
reviewed Approve How to “derive” the wave equation without refering to strings?
16h
reviewed Approve Application of surface tension in thermodynamics
1d
reviewed Reject Flow between two infinite plates