S*********g
发帖数: 5298 | 1 重整化实际上就是算出个effective field theory。
把高能部分积分掉得到低能部分的effective theory
如果说做习题的话，我想其实都不难。
倒是可以分出一个繁还是不繁。
倒是真正做research的话，
在凝聚态方面其实就是靠经验和知识的积累。
没感觉需要太多的繁琐的计算。
（做粒子和高能的除外，他们也许需要算很多圈图什么的）
其实看的paper多了，想的次数多了，某些重要概念就会理解透了，
譬如goldstone mode，renormalization，quantum phase transition。 | S*********g
发帖数: 5298 | 2 Well, QM is more than solving problems.
Solving problem is a mathematical problem.
But, understand a experiment is a totally different thing.
Most mordern concepts is impossible in classical world.
To name a few:
Band theory
off-diagonal long range order
quantuam phase transition
Bose-Einstein condensation
However, the principle behind these concept is really simple.
This principle is only about operator, physics quantity and measurement.
My suggestion to learn QM is to read Dirac's famous book. | l**********n
发帖数: 72 | 3 QM was quite ugly the first time I saw it. I guess the reason is that I get
used to classical physics very well and also deal with clear, definite,
deterministic physical processes, like the interaction between the electrons
are determined by the potentials between them and they have their own
trajectories and everything is predictive.
But what's intrinsic inside the QM is the superposition principle!
That means whenever we need to describe the physical processes, we need to
include ALL the poss
【在 S*********g 的大作中提到】
: Well, QM is more than solving problems.
: Solving problem is a mathematical problem.
: But, understand a experiment is a totally different thing.
: Most mordern concepts is impossible in classical world.
: To name a few:
: Band theory
: off-diagonal long range order
: quantuam phase transition
: Bose-Einstein condensation
: However, the principle behind these concept is really simple.
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