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A particle has spin $\hbar/2$. A measurement is made of the sum of x and z components of its spin angular momentum.
What are the possible results of the measurement?
I was reading about the one-dimensional tight-binding Hamiltonian (TBH) $$H=E_0\sum\limits_{n}|n\rangle\langle n|-t\sum\limits_{n}\Big(|n\rangle\langle n+1|+|n+1\rangle\langle n|\Big)\tag{1}$$ where $E_0$ and $t$ denote the on-site energy and the hopping parameter, repectively. The Hamiltonian of...
Is it possible to define quantum mechanics in real vector spaces instead of complex vector spaces and what would the dimensionality be of such a vector space?
Can anyone referee me such a treatment of a 2 state system, say the spin system.
This is a problem from Discrete Mathematics and its Applications
Here is my book's definition on countable
and definition of having the same cardinality
The only example that my book gave of uncountable set was the set of real numbers. I understand that because if you try listing out all ...
If we look at the axioms of Peano arithmetic, e.g. http://mathworld.wolfram.com/PeanosAxioms.html, they contain an axiom:
If $a$ is a number, the successor of $a$ is a number.
However, the axioms do not limit how many times we could apply this successor operation. So we could apply successor to...
I should note that this is an integration algorithm and therefore intermediate steps DO appear to be unjustified. The purpose of this question is to justify or reject this algorithm as always giving correct solutions.
Suppose we have some piecewise continuous function $f$ and that it can be writ...
Let $P$ be an uncountable linear ordering. Is it true that either $P$ contains an order-copy of $\omega_1$ or there is $x_0\in P$ such that there exist uncountably many distinct $y\in P$ with $y< x_0$? If so, where can I find a reference for this?
Thank you.
Suppose that there exists functions $f$ and $g$ defined on the real numbers and differentiable everywhere. If their derivatives $f'$ and $g'$ are linearly independent on some nonzero interval then are $f$ and $g$ linearly independent on the same interval? Similarly if $f$ and $g$ are linearly ind...
What if observation does not include "understanding"? For example, what if a 9 year old boy who knows nothing about QM is the observer? Does the wave function collapse? Further, if the observer has no understanding of exactly what they are observing but can relate their observation to someone who...
I'm new here and I found out that you can't post duplicate questions, but mine is a bit obsure but I hope it is ok.
I was wondering if this type of time travel: http://tvtropes.org/pmwiki/pmwiki.php/Main/GroundhogDayLoop is possible. You see, as this type of time loop (not to be confused with a ...
Imagine a qubit, who's physical support is an electron.
If its information is the spin, how could we change the spin of the electron?
It can have two spins, so I thinks that to change it, you have to make it absorb a photon.
Also, and most importantly, how do you measure its spin not only once, ...