tea-and-textbooks

[tea-and-textbooks]

One day I will make my obsidian look as nice as this one.

૮₍ ´ ꒳ `₎ა

my obsidian notes lately ⋆｡°✩

(divider in first pic is by saradika-graphics)

[tea-and-textbooks]

Some photos from my trip to Bristol Botanical Gardens. Its my favourite spot to visit on the weekends and just relax.

I kinda forgot about this blog and that is why I haven't updated you all in a while. I am hoping to do a better job at keeping this blog up to date with my daily studies, writing, and photography stuff.

[tea-and-textbooks]

Misa Explains 1: Spintronics in a nutshell

A series of posts where I will explain bits and pieces of physics I have gathered throughout the my foray into this wonderful science. Warning, these will be long.

Highly inspired by @chemblrish and @minmin-vs-physics 's posts on their fields, check out their posts (linked on this post in various places!)

Wait what even is going on?

Okay, first of all, why are we even talking about spintronics, whatever that means? Now, we live in an age where we need devices, right? Phones, TVs, laptops, name it. All digital devices come under electronics, which is a cluster of what we call "logic devices" (verrry loosely speaking) with various functions, made with expert circuitry to create our sophisticated "smart" devices. Whew. That's a lot of words. But what does it mean? It means that the very device you're using to view this post is made up of very tiny mini devices, which are made to utilize electrical signals (current, flow of electrons) to make it store information, read information, or perform logic tasks ("AND", "OR" "NOT" and the rest. Let me know if you want me to explain those, but this is not the point of the post so I'm letting them hang in the air for now).

We store digital information in the form of 'bits' (I swear all of this is relevant, please be patient) which is a computer's language of storing and using information. If you've watched any show involving hacking, you'll see stacks after stacks of "1"s and "0"s on their high contrast screens in that radioactive green font (general older sister advice: don't use high contrast it hurts your eyes), these are bits and the basis on which logic devices work. Each combination of 1s and 0s makes a different information, which is the backbone of computing. Now, how these devices make 1s and 0s is again a whole course on electronics, so I will skip over it to just preface that they exist and that's how we make digital devices.

All these years, we have used semiconductors, which allow moderate amount of current flow from them (in contrast to conductors, which allow free flow of electrons, and insulators, which do not allow flow of electrons) to make transistors, which are currently the building blocks of circuit-making devices.

[here's a picture containing ICs (the bug-like looking thing covered in wires) which have tiny transistors inside them, and the LEDs, on which the lit ones are "1"s and unlit ones are "0"s. This was my project for one of my courses!]

In electronics, a very famous law called Moore's Law, states that for increase in tech and development, the amount of transistors in integrated circuits (IC) doubles every two years. This moves proportionally with the increase in use of semiconductors, because transistors are made using them.

Every device maker's main goal is to make a device faster, smoother, and more functional. Which means, more transistors, better semiconductors. Moreover, the smaller space occupied by the ICs, the better. But obviously there's a limit to how much we can decrease the size of the transistors. One is the technical issue of creating such a small object, which will require highly precise instruments which we are not in possession of/ not feasible in the long run. The second issue is the working. "Will a semiconductor keep it's properties when they layer is so small?" is a valid question to ask when we go further down in scale. In simple words: in the long run, improving semiconductors for transistors will be difficult. Moore's law plateaus, and the number of transistors doesn't double with two years. What now? We can't just stop developing better computing devices, not just smart devices, astronomy, medicine and other scientific areas also require reliable, stable and fast computing devices.

Which means we desperately need new materials (and techniques) for logic and memory devices.

Hold on, when's spintronics going to start?

Okay background information done. Now we move onto spins and why we use it. We know that atoms are made of protons, electrons and neutrons. Out of these, electrons "revolve" in "orbits" around the nucleus, which holds the protons and neutrons. I put "revolve" and "orbits" in quotes because essentially it's a cloud of probabilities and we have no clue what path it truly takes. Electrons reside in what are called 'orbitals', which are balloon-like spaces which have a high probability of the electrons being present in (@/chemblrish explains orbitals better here).

Now along with the "revolution", electrons also considered to have a "spin". We don't really know if it "spins" the way Bayblades do, but regardless, they have an angular momentum, which is classically something rotating objects possess (@/mimin-vs-physics goes more in depth on quantum mechanical fun stuff) Either way, we don't know why it has angular momentum, but we know it does (at least I have no idea if we've figured it out??). And in true human fashion, we see anything new and think "now how can I utilize this for my benefit?"

Years and years of research later, we figured out something interesting. The angular momentum which the electron spins contain, and the angular momentum of electrons in "orbits" can interact! This interaction is called Spin-Orbit Coupling (SOC) and it causes a bunch of other fascinating phenomena in quantum mechanics. One of which, is that it if we supply electricity into a metal plane, we can align the electrons and their spins in such a way that it causes a stream of current (remember: current is essentially a flow of electrons in one direction) with aligned spins to move into a different layer perpendicularly.

Okay but what does all of this have to do anything with Spintronics?

We're finally at the part where we can discuss what Spintronics is! We can use our now generated spin current to make electronic devices (hence, spintronics!). So, how do we make these tiny devices?

What we first take is a heavy metal (these are metallic elements/alloys with high atomic numbers, which have a lot of free electrons to use) and make a very thin film of it. (The procedure of making thin films is very interesting, and I will make the next post on it!) We can now pass a stream of current/electricity* parallel to the surface of the thin film, which will give us a stream of spin-aligned electrons bouncing to move into an upper layer.

For the upper layer, we add a thin layer of a ferromagnet. A ferromagnet is a type of material which readily aligns its spin on one direction when under a magnetic field (contrary to this are paramagnets which weakly align their spins, and diamagnets which weakly align their spins opposite to the applied field).

Now remember the electrons with their spin aligned which wanted to move into the upper layer? Yeah once they are given an upper layer to move into, they flow into the layer, bringing their aligned spins with them. This spin can now affect the ferromagnet's spin, and align it in either the direction of the applied electric field ( the one applied on the heavy metal layer. I'm marking it as * for you to check which electric field I mean) or directly opposite to the direction of the electric field. This alignment can be measured. The value doesn't matter, only the direction. Is it parallel to the electric field or anti-parallel? "Up" or "down"? "Left" or "right"? Or, in terms of electronics, "1" or "0".

And look! We now have a way to make a tiny device which can display values of "1" or "0"! We used an analog signal (electricity) to create a digital output (1s and 0s)! That is electronics! But because it uses spins, it is called Spintronics.

Because we use Spin-Orbit Coupling, these devices are extremely precise and fast. And the layers of heavy metal/ferromagnet will be in the ranges of nanometers (10^-9 m), so they are also extremely small. We can also choose materials with properties we like (high melting/boiling point, low reactivity) to create devices which can work in extreme conditions (high heat, pressure, reactive areas).

And here we have it! We've made spintronic devices!

End of post disclaimer: I am a Bachelors student and I will have mistakes. I also tend to exaggerate. So if I have made a mistake in this post, please inform me nicely in the comments or tags!

[tea-and-textbooks]

October 24th, 2024

Busy day, too busy for my taste but had some nice moments. One more day and I'll have a week off. I am really looking forward to not having to get up with an alarm. That makes such a big difference for me.

[tea-and-textbooks]

₊˚✧October 24, 2024 ✧˚₊‧

I been a bit busy today so I didn't do too much studying today. I did write some notes on my obsidian and I also practiced some Finnish vocab. My day was pretty uneventful for the most part.

What I dd today:

I cleaned up my room

Had a few appointments

Ran a few errands

Wrote a few notes in my obsidian

Practice some Finnish Vocab

What I would like to do tomorrow:

I would like to go to a cafe and relax a bit

Read some more of my book (Gathering moss by Robin Wall Krimmer)

Do some more language lessons

Do another photo dump of my aquarium and botanical garden trips

Water and prune my house plants

[tea-and-textbooks]

₊⊹ Mini Photo dump of some of my favourite photos I took at the botanical garden ₊⊹

[tea-and-textbooks]

₊˚✧October 22, 2024 ✧˚₊‧

I am so sorry for the really long hiatus. I have been dealing with chronic illness lately. I am feeling so much better now. I am so excited to get back to studying. Here are a few updates over the past month and a bit I was off. I got my first ever hobonichi I have always wanted to try one. I got the hobonichi cousin with the orange Mr. Saturn cover. (i got the orange cover so I can find it easily.) I decided to redo my obsidian set up to make my note taking process a bit more seamless. I went to the aquarium and the botanical garden while i was on hiatus so I will be posting some photos soon. Thats all I have for updates I spent the last month mostly resting.

What I did today:

I transfered some of my paper notes to my obsidian

I practiced my finnish vocabulary

I also practice my potawatonmi vocabulary

I am currently reading a new book Gathering Moss bty Robin Wall Kimmer ( I really love her work)

What I would like to do tomorrow:

I would like to read a bit more of my book

I would also like like to do some more langage lessons

I would also like to upload some of the aquarium photos and videos tomarrow..

[tea-and-textbooks]

‎‧₊˚✧September 9, 2024 ✧˚₊‧

I have been so busy the past few days, I have been feeling kinda bad about not studying and havent felt productive the past few days. I think I have sorted out all my stuff so I can finally have some time to study agian. I have some small updates, I finally bought my own copy of the "Teach yourself - Complete Finnish" because I cant renew the one for the library for a while. I also got some new cat shaped sticky tabs. They are soooo cute!

What I did today:

I went to the city centre and got some stationary and a white board

I got my own copy of complete Finnish

I practiced my Finnish and Potawatomi vocabulary

What I Want to do tomarrow:

I am going to the aquarium with my partner so i might be a bit busy

I would like to practice more Potawatomi

I would also like to get a bit more reading done

[tea-and-textbooks]

this week has been actually exhausting for me, i have been sick for a couple of days and i had a very packed work schedule along with lots of things i needed to study for but somehow i survived the hectic days and can finally take a long rest.

[tea-and-textbooks]

‎‧₊˚✧September 2, 2024 ✧˚₊‧

I am so sorry for the long hiatus, I just have been dealing with a few things. But I had a bit of time today and was able to do a bit more book annotating.

I annotated a bit more of Braiding Sweetgrass by Robin Wall Kimmmer

I also cleaned my desk a bit

I have also been harvesting a lot of Marigold from my little herb garden.

[tea-and-textbooks]

˚✧August 26, 2024 ✧˚₊‧

I haven't been feeling too good the past few days so I have been resting. But I am feeling a bit better today. So hopefully I can get some studying done tomorrow. I hope you all have been doing well.

[tea-and-textbooks]

⋆˚࿔ Potawatomi Notes 𝜗𝜚˚⋆

I did my Unit 1 chapter 2 Potawatomi language lesson notes a few days ago and forgot to post it. ( ˶o´ ̫ `o˶)

[tea-and-textbooks]

Looking for active studyblrs and gradblrs to follow!

Hi!! My name is Kinoko and I'm working on my masters in addiction counseling and clinical counseling. I absolutely bombed the summer semester, so I'm looking for some inspiration and motivation!

Pls like or reblog if you're an active studyblr 🤗

[tea-and-textbooks]

August 22nd, 2024. Thursday.

🐬 Well, I woke up at 11pm. Usually I wake up at 3 or 4am so this was a big surprise. Starting to take after my pastry chef mother for sure.

🦈 It's 5am currently. I have two more hours until I need to leave to go grocery shopping. With my promotion to a better position (that somehow pays less), money is tight. I'm setting a $50 budget for food for each week. Gonna be a struggle.

👑 Things I've gotten done so far today:

Wrote a Slowly letter. Been procrastinating that.

Relaxed for an hour. SO necessary and I neglect self-care SO bad!

Completed all the homework for the week for school.

Drafted and submitted 3 different scholarship essays

Drafted 5 chapters of my book, Rot. Hoping to get it all drafted before August ends.

I'm hoping to deep-clean 3 areas of my room before I head to work today. It's gotten SO messy in here and it's honestly overwhelming. Something needs to change!

What have been your biggest goals lately? How are you breaking it down into bite-sized pieces?

Talk more soon!

[tea-and-textbooks]

what would you say are some major differences between uk students compared to your us peers (just academically)?

I haven't really noticed too much of a difference really, the only real difference that has been really noticeable is the terminology they use when talking abbot school stuff. Like British people don't use terms like Major, Minor, SAT, Sophomore, Junior, Senor . ( I do live in England, so it just might be a English thing)

The hardest part for me is trying to learn all of the terminology they use when talking about their experiences in school. So stuff like GCSE, A levels, Collage, Sixth forum, and stuff like that.

[tea-and-textbooks]

‎‧₊˚✧August 21, 2024 ✧˚₊‧

I did quite a bit today. I went to the city centre to go to the library. My partner needed to get a book they reserved. I looked around the library and found a book on natural soaps and another book called how to write about Africa. Thy seemed really interesting so I decided to check them out. After the library we went to a café and had a drink. Then we went to the Asian Market to get a few snacks and headed back home. I spent the remainder of the day writing more notes in my obsidian, as well as working on Chapter 1 Unit 2 of my Potawatomi lesson. I have also read more of my Complete guide to Finnish.

What I did Today

Went to the library and checked out 2 new books. I checked out The Handmade Spa by Amélie Boué and How to Write About Africa by Binyavanga Wainaina

went to a local café and had a drink with my partner

went to the Asian Supermarket to get a few snacks

Sat by the Warf and had snacks and a chit chat with my partner

wrote some more notes in my obsidian

Worked on my Potawatomi lesson on Mango

Read some more of the complete guide to Finnish

What I would Like to do Tomarrow

Look into getting a Hobonichi

Finnish annotating Braiding Sweetgrass

Start reading one of my new library books

[tea-and-textbooks]

absolutely loving my new desk set up in my university apartment !!