cant undersand this example..(quantum mehanics) - Electronic Circuits Projects Diagrams Free

transgalactic · 26th September 2009, 07:18 PM

http://physweb.bgu.ac.il/COURSES/PHY...hysics3_c1.pdf

in the 13 page.
i cant understand those symbols arrows
etc..

skyhawk · 27th September 2009, 01:18 AM

The symbols are used to indicate the state of a spin 1/2 particle. The arrows indicate spin up (m = 1/2) or spin down (m = -1/2). The representation of these states in terms of column vectors is given in the middle of the page. They are operated on by the various 2x2 matrices called the Pauli matries.

transgalactic · 27th September 2009, 07:22 AM

i dont know what . "The arrows indicate spin up (m = 1/2) or spin down (m = -1/2)"

where can i learn about this stuff more thurely,

maybe its a chapter of new math(i know multivariable calculus)

?

skyhawk · 27th September 2009, 02:37 PM

Multivariable calculus is not much help with this part of quantum physics. Basic matrix algebra is necessary. This really requires a lot of background knowledge that should be provided by your instructor. I don't know how you can be expected to work problems without the necessary information.

Here are a couple references that may help:

Electron spin

Spin-½ - Wikipedia, the free encyclopedia

Feyman Lectures in Physics Vol 3 is a good reference on basic quantum mechanics. They can be downloaded from scribd.

To be honest I don't see how you can be expected to do this work without good lectures from your instructor. This is hard material. I wish you good well.

transgalactic · 3rd October 2009, 09:10 PM

is this the correct course
MIT OpenCourseWare | Chemistry | 5.74 Introductory Quantum Mechanics II, Spring 2004 | Video Lectures

skyhawk · 3rd October 2009, 11:11 PM

Too advanced and the professor is boring.

This course might be useful. I've just started looking at the videos.

YouTube - Lecture 1 | Quantum Entanglements, Part 1 (Stanford)

transgalactic · 3rd October 2009, 11:14 PM

does it fit with this syllabus
http://physweb.bgu.ac.il/COURSES/PHY...neous/plan.pdf
?

i looked at the lecture you proposed
and the lecturer says thats its for older people
and not for freshmen
so i cant decide if it fits me

skyhawk · 3rd October 2009, 11:23 PM

I don't know, probably not exactly.

I've searched quite a bit and haven't yet found a good set of lectures on quantum mechanics.

transgalactic · 3rd October 2009, 11:32 PM

so the course you proposed is by my syllabus
?

skyhawk · 3rd October 2009, 11:54 PM

I don't think you are going to find a set of video lectures that corresponds exactly to your syllabus. There are going to be lectures that correspond to various topics in the syllabus.

The lecturer sounds like he is going to discuss spin and Dirac notation, and perhaps inner products. How long it takes him to get there, I don't know.

The best that I can tell you is to look at each lecture, and see if it contains anything useful to you for your course.

skyhawk · 4th October 2009, 03:19 AM

You can skip the first hour of lecture 1, but starting at around 1:00 he begins talking about math that we have been discussing. Lecture 2 starts the discussion of electron spin and the math used to describe it. Lecture 2 is very good. It should answer many of the questions you had at the start of this thread.

YouTube - Lecture 2 | Quantum Entanglements, Part 1 (Stanford)

skyhawk · 4th October 2009, 06:28 PM

Lecture 3 covers the postulates of quantum mechanics, some general theorems, and the mathematics of spin 1/2 particles in much detail. There is much work with the Pauli matrices although he doesn't use the term. All relates to the original question on this thread.

YouTube - Lecture 3 | Quantum Entanglements, Part 1 (Stanford)

Thread Tools
Show Printable Version Email this Page
Display Modes
Linear Mode Switch to Hybrid Mode Switch to Threaded Mode

Similar
Title	Starter	Forum	Replies	Latest
need Quantum Mechanics for Scientists and Engineers	zavedur rahman	Math and Physics	5	8th May 2008 10:57 PM
Quantum Dots for solar power can now use infrared	williB	General Electronics Chat	1	14th February 2005 04:29 AM
Use of Quantum	shri.v.krishna	Electronic Projects Design/Ideas/Reviews	3	7th November 2004 01:13 PM
Use of Quantum	shri.v.krishna	Electronic Projects Design/Ideas/Reviews	0	19th October 2004 11:35 AM

26th September 2009, 07:18 PM	#1
transgalactic	cant undersand this example..(quantum mehanics) http://physweb.bgu.ac.il/COURSES/PHY...hysics3_c1.pdf in the 13 page. i cant understand those symbols arrows etc.. Last edited by transgalactic; 26th September 2009 at 07:18 PM.

27th September 2009, 01:18 AM	#2
skyhawk	The symbols are used to indicate the state of a spin 1/2 particle. The arrows indicate spin up (m = 1/2) or spin down (m = -1/2). The representation of these states in terms of column vectors is given in the middle of the page. They are operated on by the various 2x2 matrices called the Pauli matries.

27th September 2009, 07:22 AM	#3
transgalactic	i dont know what . "The arrows indicate spin up (m = 1/2) or spin down (m = -1/2)" where can i learn about this stuff more thurely, maybe its a chapter of new math(i know multivariable calculus) ? Last edited by transgalactic; 27th September 2009 at 07:23 AM.

27th September 2009, 02:37 PM	#4
skyhawk	Multivariable calculus is not much help with this part of quantum physics. Basic matrix algebra is necessary. This really requires a lot of background knowledge that should be provided by your instructor. I don't know how you can be expected to work problems without the necessary information. Here are a couple references that may help: Electron spin Spin-½ - Wikipedia, the free encyclopedia Feyman Lectures in Physics Vol 3 is a good reference on basic quantum mechanics. They can be downloaded from scribd. To be honest I don't see how you can be expected to do this work without good lectures from your instructor. This is hard material. I wish you good well.

3rd October 2009, 09:10 PM	#5
transgalactic	is this the correct course MIT OpenCourseWare \| Chemistry \| 5.74 Introductory Quantum Mechanics II, Spring 2004 \| Video Lectures

3rd October 2009, 11:11 PM	#6
skyhawk	Too advanced and the professor is boring. This course might be useful. I've just started looking at the videos. YouTube - Lecture 1 \| Quantum Entanglements, Part 1 (Stanford)

3rd October 2009, 11:14 PM	#7
transgalactic	does it fit with this syllabus http://physweb.bgu.ac.il/COURSES/PHY...neous/plan.pdf ? i looked at the lecture you proposed and the lecturer says thats its for older people and not for freshmen so i cant decide if it fits me Last edited by transgalactic; 3rd October 2009 at 11:21 PM.

3rd October 2009, 11:23 PM	#8
skyhawk	I don't know, probably not exactly. I've searched quite a bit and haven't yet found a good set of lectures on quantum mechanics.

3rd October 2009, 11:32 PM	#9
transgalactic	so the course you proposed is by my syllabus ?

3rd October 2009, 11:54 PM	#10
skyhawk	I don't think you are going to find a set of video lectures that corresponds exactly to your syllabus. There are going to be lectures that correspond to various topics in the syllabus. The lecturer sounds like he is going to discuss spin and Dirac notation, and perhaps inner products. How long it takes him to get there, I don't know. The best that I can tell you is to look at each lecture, and see if it contains anything useful to you for your course.

4th October 2009, 03:19 AM	#11
skyhawk	You can skip the first hour of lecture 1, but starting at around 1:00 he begins talking about math that we have been discussing. Lecture 2 starts the discussion of electron spin and the math used to describe it. Lecture 2 is very good. It should answer many of the questions you had at the start of this thread. YouTube - Lecture 2 \| Quantum Entanglements, Part 1 (Stanford)

4th October 2009, 06:28 PM	#12
skyhawk	Lecture 3 covers the postulates of quantum mechanics, some general theorems, and the mathematics of spin 1/2 particles in much detail. There is much work with the Pauli matrices although he doesn't use the term. All relates to the original question on this thread. YouTube - Lecture 3 \| Quantum Entanglements, Part 1 (Stanford)