QuantumATK Forum
QuantumATK => General Questions and Answers => Topic started by: renren123123 on September 15, 2009, 05:17
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Recently, I calculated a simple system adoping spin-polarized, as we know, the results consist of spin-up and spin-down parts, the current is like this, according to above description, we want to see clearly following definations:
1. spin-polarized current or spin current in my calculation?
2. if it is spin-polarized current or spin current, is the value the sum of spin-up and spin-down current? or half of them? can be observed in experiment for each kind of spin-polarized current?
3. which one is better for spin-dependent or spin-polarized in calculation of ATK?
thank you very much!
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Recently, I calculated a simple system adoping spin-polarized, as we know, the results consist of spin-up and spin-down parts, the current is like this, according to above description, we want to see clearly following definations:
1. spin-polarized current or spin current in my calculation?
2. if it is spin-polarized current or spin current, is the value the sum of spin-up and spin-down current? or half of them? can be observed in experiment for each kind of spin-polarized current?
3. which one is better for spin-dependent or spin-polarized in calculation of ATK?
First, suggest you to read some reference to understand the definition of spin current:
Qing-feng Sun and X. C. Xie, Phys. Rev. B 72, 245305 (2005), Definition of the spin current: The angular spin current and its physical consequences, http://prola.aps.org/abstract/PRB/v72/i24/e245305 (http://prola.aps.org/abstract/PRB/v72/i24/e245305)
For your 1st question, what you calculated is the spin-polarized current, or spin-resolved current (i.e., the spin-up and spin-down parts).
For your 2nd question, the sum of spin-up and spin-down currents should be the total current, rather than the spin current. As argued in literature, spin current may not be defined simply as the difference between the spin-up and spin-down current.
For your 3rd question, both are acceptable.