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QuantumATK => General Questions and Answers => Topic started by: physics on December 6, 2023, 12:24

Title: Manual magnetic moment variation and device creation with interface
Post by: physics on December 6, 2023, 12:24

Hi everyone,

Is it possible to change the magnetic moment of a hetero structure device manually (let's say 0.4, 0.5. ...etc.), instead of calculating it. Also, is it possible to create an interface like Silver electrode (left electrode), then silver copper (central region) and then copper (right electrode).

Thank you

Title: Re: Manual magnetic moment variation and device creation with interface
Post by: Anders Blom on December 9, 2023, 00:50

First part is not possible, that I can see, if you mean you want to constrain the moment. You can of course provide an initial guess for it via InitialSpin, but then it will adjust during the self-consistent cycle.

For the second question, the answer is yes.

Title: Re: Manual magnetic moment variation and device creation with interface
Post by: physics on December 11, 2023, 12:51

Thank you for the reply.

Please suggest the possible tutorial to build the proposed device. I am looking for tutorial where the central region include two different materials (in this case AgCu).

Title: Re: Manual magnetic moment variation and device creation with interface
Post by: AsifShah on December 11, 2023, 15:18

You can simply look into interface builder tutorial of QuantumATK.
its pretty easy to use.

Title: Re: Manual magnetic moment variation and device creation with interface
Post by: physics on December 11, 2023, 16:02

Hi,

 I looked into the interface builder tutorial. But the interface is like having same electrode (lets say Ag) and central region (lets say Cu). But I want to build like Ag (left electrode), AgCu (central region, I want some part of electrode metal which is Ag in central part as well), and then Cu (right electrode).

 Please advise.

Title: Re: Manual magnetic moment variation and device creation with interface
Post by: AsifShah on December 11, 2023, 16:49

Did you mean like this as shown in the figure?

Title: Re: Manual magnetic moment variation and device creation with interface
Post by: physics on December 11, 2023, 17:09

Yes.

Title: Re: Manual magnetic moment variation and device creation with interface
Post by: AsifShah on December 12, 2023, 06:43

I will write here steps to follow:
1. Choose Silver from database.
2. Search Surface (Cleave) in the right section of builder. Click on cleave and write 111 for miller indices and then keep hitting Next till end.
3. At last you will have a 3 atom Ag supercell.
4. Do same for copper.
5. Then bring both 3 atom cleaved Ag and Cu supercells into the interface builder and form the interface with lowest possible strain that you want.
6. Just below the drop boxes in interface builder you will see +/- buttons. Hit + to increase number of atoms on each side of Ag and Cu.
7. Make interface.
8. Go to device and there you have it.

PS: In device configuration try increasing electrode extension. Generally, metals require less screening length in electrode extension so you can keep the around 2 nm maybe, though check the electrostatic difference potential later if it converges or not (then increase it further).

Title: Re: Manual magnetic moment variation and device creation with interface
Post by: physics on December 12, 2023, 11:22

Hi,

Thank you for the reply. It worked well.