Ultracold science finds new method to get even colder

Researchers have developed a clever way to achieve the coldest temperatures ever recorded on Earth.

Achieving such temperatures is necessary to study fundamental properties of matter and the strange effects caused by quantum mechanics.

The new method relies on "optical lattices" of atoms from which only the hottest atoms are selectively removed.

The approach, reported in Nature, may be well-suited to create memory for future quantum computers...

Source





This looks interesting on two fronts. Firstly the achievement itself, then the suggested application, what with effective quantum computing being the holy grail of so much current research...

interesting. so instead of the standard method of draining out as much energy as possible, they're physically removing the atoms that have the highest energy levels.

i could use a quantum computer right about now. just got "the witcher 2" and its very demanding.

Originally posted by pause4thought
Researchers have developed a clever way to achieve the coldest temperatures ever recorded on Earth.

The new method relies on "optical lattices" of atoms from which only the hottest atoms are selectively removed.

So if I understand this technique correctly, they have a number of atoms that have a range of energies. Then they begin to remove atoms one by one starting with atoms that have the highest energies, then they remove the next highest ... followed by the next atom in sequence ... etc, etc

So when the last and final atom is removed, does this mean that theoretically they've achieved their goal and reached a condition of absolute zero ???

reply to post by tauristercus


Hang on, if they remove the last atom, there would be no temperature to measure would there?

So my understanding is, they have made a selective magnet, removing atoms 'vibrating' at higher frequencies than other atoms. Soooooo, if they get to the last atom, and it stops vibrating (zero kelvin), will this mean frosty-cup machines in every bodies kitchen?

reply to post by tauristercus


Sometimes I wonder if that -is- what Absolute Zero amounts to - nothing.

It's kind of like a super-position, in a way. The moment you interact with a hypothetical atom at absolute zero, you inject energy into the system and raise it above absolute zero. Nothing at the state of absolute zero can actually interact with the universe (else it raises above absolute zero to let the world know what... absolute zero is like... it dawns on me that makes less sense saying it than my little mental-emulation, right now).

Anyway.... seems kind of interesting. Almost like a microscopic application of evaporative cooling.

reply to post by tauristercus

absolute zero isn't possible to reach. the heisenberg uncertainty principle won't allow it. even if the heisenberg uncertainty principle could be broken (which it can't), you couldn't observe or measure it to check that you've reached absolute zero.

Originally posted by Qumulys
reply to post by tauristercus

 

Hang on, if they remove the last atom, there would be no temperature to measure would there?

My [tongue-in-cheek] point exactly !
What temperature would you measure if there was NO object with a temperature to be measured ?

If the temp drops with every atom removed, then surely removing the last atom removes the last shred of energy and doesn't that equate to absolute zero ? Think about it .....

reply to post by tauristercus


YOU BROKED MY NOGGIN!

*pulls out hair

WAIT!

When the last atom is removed, everyone turns into the Fonze. Cooooooool ;-)

reply to post by tauristercus

that's slightly nonsensical because temperature is kinetic (motion) energy at the atomic scale, so hitting absolute zero means that an atom wouldn't be moving. applying that to a vacuum doesn't make much sense.

you might be kind of right in classical physics, but nowadays since everything is being quantized, we now know that a true vacuum isn't actually empty. it's filled with particle-antiparticle pairs that pop into existence and annihilate each other very, very quickly. even "empty" space gives off energy.

Originally posted by Bob Sholtz
reply to post by tauristercus

 

that's slightly nonsensical because temperature is kinetic (motion) energy at the atomic scale, so hitting absolute zero means that an atom wouldn't be moving. applying that to a vacuum doesn't make much sense.

you might be kind of right in classical physics, but nowadays since everything is being quantized, we now know that a true vacuum isn't actually empty. it's filled with particle-antiparticle pairs that pop into existence and annihilate each other very, very quickly. even "empty" space gives off energy.

You're quite correct and anyway, I wasn't intending my posts to be taken to seriously or figuratively ... that's why I sprinkled them with and and and [tongue-in-cheek] references

But seriously, the background vacuum energy surely must guarantee that no matter what clever technological tricks are employed, that absolute zero can NEVER (at least in our current physics) be achieved in the laboratory.

reply to post by tauristercus

sorry, just trying to be helpful

most people will see this and think "so what. you've managed to make super frozen ice." but things get amazing at cold temperatures. bose-einstein condensate is THE coolest state of matter ever. super conductors will be used in everything electronic once they're perfected, and even if they didn't have a practical use, they'd still be cool.

How did they work out absolute zero, when there is no way to reference in the first place.

"Absolute", would have to mean Hypothetically Absolute based on what we know?

or am I missing a link?

reply to post by nawki

when atoms get hot, they vibrate. think of water being brought to a boil. now, once it hits 212 F, the molecules have enough energy to break away from each other and become a gas. the atoms at this level are actually whizzing around in the air because they have much more energy than room temperature water. if you go farther, the steam would become plasma, and the electrons would separate so all the atoms are a jumble of very high energy subatomic particles.

if we go in reverse, cooling water down slows the movement speed of atoms and they crystallize into ice. crystals form their specific geometric patterns based on the shape of the individual molecules that make them up (think of one honey comb attaching to a hundred others to make a much larger honey comb). the only limit to going up in temperature is the maximum speed at which something can move (lighspeed), and the theoretical bottom limit of temperature is when an atom isn't moving at all. this non-moving state is referred to as "absolute zero" because you can't go slower than something that isn't moving. however in reality, you can't reach a perfect stand still state.

reply to post by Bob Sholtz


Thank you

That does make perfect sense, I was thinking cold... not motion..

This will allow them to get closer to the mark, even though they can never reach or observe Absolute Zero.

This is very intriguing, I might do some reading into the whole thing.

Thanks again.