QuantumATK Forum

QuantumATK => General Questions and Answers => Topic started by: Dipankar Saha on February 4, 2014, 15:06

Title: Bloch states
Post by: Dipankar Saha on February 4, 2014, 15:06

How the distribution of the HOMO/ LUMO Bloch states...., can be utilized to distinguish between the S.C. and the metallic properties of any two- dimensional material....???

____Dipankar Saha

Title: Re: Bloch states
Post by: Anders Blom on February 19, 2014, 00:41

Well, a metal doesn't have any HOMO/LUMO level/band by definition...

Title: Re: Bloch states
Post by: Dipankar Saha on February 19, 2014, 15:30

Andres Blom,

Yes... But my question was some thing else....

Say a semi-metal like GNR, which was initially a S.C. .... has eventually become metallic due to certain perturbations.../ This can be verified from the Band Diagram.... / Now the Homo/Lumo bloch states distribution, in case it was S.C. has also been found.
But, the question is...
i) how those bloch states distribution will vary, when it is perturbed???

ii) If the bloch states are distributed across the surface, or at the edges, or at the core.....how that should be interpreted ???

Thanks & Regards__
Dipankar Saha

Title: Re: Bloch states
Post by: Anders Blom on February 19, 2014, 16:17

Too general question to answer easily.

Title: Re: Bloch states
Post by: Dipankar Saha on February 19, 2014, 18:22

Sir,

An elaborate discussion regarding the same topic (with due example and diagrams) was initiated a few months ago....
But, unfortunately the discussion ended..without reaching any conclusion.....;
and this can be seen in....
http://quantumwise.com/forum/index.php?topic=2506.15#.UwTnWfmSwYA

Anyways, it would be very helpful ...if you can please give us a clear-cut inference....regarding the topic....

Thanks and Regards__
Dipankar Saha

Title: Re: Bloch states
Post by: Anders Blom on February 19, 2014, 22:30

I must admit I don't fully grasp what the real question is. The Bloch states are wave functions, so if they reside on the edges it means this particular state does so, but there are many states... I don't think you can draw any huge conclusions at all by just looking at a particular Bloch state isolated, at least not without motivating why this particular state is so interesting. Obviously if the majority of all Bloch states travel along the edges it means if you place a defect precisely there you have a big effect - this has been demonstrated to be an effective way to implement a spin filter, for instance.

Title: Re: Bloch states
Post by: Dipankar Saha on February 21, 2014, 12:57

A. Blom,

Okay..../ Thank you sir... :)

Regards__
Dipankar