Is anyone into quantum technologies and quantum metrology?

[branadic]

Good evening,

I wonder if anyone is into quantum technologies and metrology, beside JVS? So something like vapour cells, NV-centers, ... Even if just one a research level, I would be interested to hear what you are working on and what you have achieved as of now.

-branadic-

[KE5FX]

I've wanted to build an Rb MOT ever since I saw one demonstrated at a NIST seminar, but just haven't gotten a round tuit (or a spare $15K or so to buy one off the shelf from ColdQuanta^WInfleqtion.)  Does that count?

[thermistor-guy]

Thermometry is my thing, so I am interested in quantum dots as optical temperature sensors e.g.

https://link.springer.com/article/10.1007/s11051-019-4629-8

No achievements. Unfortunately I have several projects lined up ahead of that one, including one
on temperature-sensitive Ruby fluorescence. So lessons learned there might carry over to QDs.

[dietert1]

Any physicist doing precision measurements can dream of discovering previously unknown effects. Of course it depends on his/her resources, but also it may be luck. Technology is a statistical precondition for new discoveries and patents.

Regards, Dieter

[zrq]

After working for around 2 years for a cold atoms/atom vapour magnetometry research group, I would not make that as a hobby, simply too expensive and time consuming...

[KE5FX]

Well, that's kind of the idea behind a hobby, now, isn't it?

[coppercone2]

i feel like its really hard to get that equipment and also the whole idea of maintaining a stock pile of coolant is really lame for a hobby

[KE5FX]

the whole idea of maintaining a stock pile of coolant

That's, uh, not how it works.

[nimish]

Good evening,

I wonder if anyone is into quantum technologies and metrology, beside JVS? So something like vapour cells, NV-centers, ... Even if just one a research level, I would be interested to hear what you are working on and what you have achieved as of now.

-branadic-

NIST will sell you a Josephson junction array on a chip for ~$300k. Perfect voltage standard as of 2019.

[coppercone2]

the whole idea of maintaining a stock pile of coolant

That's, uh, not how it works.

most quantum technologies require a shit load of cryogenic coolant.

[zrq]

Well, not necessary true. For many cold atom experiments one don't need cryogenics, but in fact a heated oven to generate a beam of atom to be Zeeman slowed and loaded to a MOT.... For the projects using warm vapor it's more obvious.

[coppercone2]

that is nice to know I thought liquid helium was a requirement for 95% of quantum physics.

someone should make a list of quantum apparatus that can be used without LH

[branadic]

Interesting to note that only a handful of people are into the quantum field.
I recently started with NV centers in diamand, a quantum system working at room temperature. We breadboarded the very first quantum magnetometer last week and are currently working on an improved version. But that is just the start to develope a gut feeling and to further improve the setup. I have one or the other idea what is yet to come.

-branadic-

[iMo]

Afaik all today's semiconductor lasers for optical networks are based on QD.
Would be interesting to have such a laser handy, run it at a low power, at a "constant" temperature and current and use it as a voltage source (like we do sometimes with an LED).

[zrq]

I think VCSELs are prevalent for the lowest end 850nm transceivers, and most O-band and C-band high-end devices are usually InP quantum well lasers, still quantum but not dots. QD lasers are mostly still in R&D.

[Harfner]

Would be interesting to have such a laser handy, run it at a low power, at a "constant" temperature and current and use it as a voltage source (like we do sometimes with an LED).

You mean, like an LED is sometimes used as sort-of-zener diode? Would a quantum dot laser have good voltage stability if used that way?

[iMo]

I think VCSELs are prevalent for the lowest end 850nm transceivers, and most O-band and C-band high-end devices are usually InP quantum well lasers, still quantum but not dots. QD lasers are mostly still in R&D.

It could be.. QDots, QWells, QLayers, QWires - those are today's buzzwords..

Would be interesting to have such a laser handy, run it at a low power, at a "constant" temperature and current and use it as a voltage source (like we do sometimes with an LED).

You mean, like an LED is sometimes used as sort-of-zener diode? Would a quantum dot laser have good voltage stability if used that way?

Yes, no idea..

[coppercone2]

the most interesting thing about quantum dots is is that its just fine powder. I think the name is super marketing. Because really, its a fine powder, treated with basically anti caking coatings, much like table salt. 

how about semiconductor meal. and angel hair wire.



I felt a little cheated when I found out what quantum dots actually were.

[vonB]

Hello guys.

Im currently working in quantum technologies as ee

Something about quantum computers and quantum key distribution

[iMo]

Quantum Dots.. a lot of them..

https://www.samsungdisplay.com/eng/tech/quantum-dot.jsp

 

[branadic]

After building first NV-based setups with microdiamonds to demonstrate Quenching we went forward and build our first ODMR/Zeeman splitting setup using a discrete build Omega resonantor based on some SMA posts that were soldered together with 1 pF Mica capacitor and a magnet wire loop in between. After some tweaking of the lenght of the magnet wire we achived a nice 2.87 GHz resonance frequency. 

I now wanted to go a step further using planar Omega resonators. There are quite a few publications out there addressing this topic, which would be a good starting point for simulation, replication and adjusting to individual needs, such as: Antenna for microwave manipulation of NV colour centres

As my pocket is not that deep I tried simulating the geometry from the aforementioned paper using Sonnet Lite. I think I have setup everything properly. Unfortunately, the simulation is far of from what I expected (see images attached). Is anyone into RF simulation and can help?
Is there any other free tool for such tasks?

-branadic-

[RoGeorge]

Something about quantum computers and quantum key distribution

Is that about using quantum encryption with classical computers, or does it includes hardware quantum computers, too?
 
I am curious about the hardware implementation of quantum computing in general, and about how are they built in practice (depending on which type of quantum phenomena they are based on).

[KE5FX]

As my pocket is not that deep I tried simulating the geometry from the aforementioned paper using Sonnet Lite. I think I have setup everything properly. Unfortunately, the simulation is far of from what I expected (see images attached). Is anyone into RF simulation and can help?
Is there any other free tool for such tasks?

-branadic-

Post the Sonnet Lite file?

[branadic]

I have attached the file to the former post.

-branadic-

[moerm]

I looked around but found no provider for "quantum technologies in the cloud", so my answer is 'No'. After all, everything and anything must be done in the cloud nowadays or else it's not really modern and high-tech.

(Side note: I actually studied Physics but never got interested in quantum-[whatever]. Please take the above as tongue in cheek ...)

[nctnico]

Good evening,

I wonder if anyone is into quantum technologies and metrology, beside JVS? So something like vapour cells, NV-centers, ... Even if just one a research level, I would be interested to hear what you are working on and what you have achieved as of now.

Not really into doing quatum stuff myself but as I'm deeply entangled into high-precission (tens of picoseconds) time transfer over long distance, I am and have been involved with quite a few research projects around quantum technology to allow measuring quantum related effects spanning great distances. Interesting stuff but it takes some reading to understand what the projects are actually about. The scientist are typically so deeply submerged in their research that they have a hard time explaining their project in a way somebody not involved with it can understand what they are on about.  Very interesting to have a front row seat though.