5:57 PM
Welcome to chat for: Quantum Computing
10
This is a general discussion room, but please feel free to create more subject-specific rooms (a single room with every possible discussion isn't very helpful)
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1 hour later…
Anonymous
7:08 PM
Hi everybody!

Hello!

Hi @Everyone :)

'lo

Anonymous
When did this chat get activated?

Anonymous
7:09 PM
Just noticed now

17:57 UTC by the looks of it

Anonymous
I see. Awesome :)

@Pavel Possibly edit in a link to the room? For some reason I can't

Anonymous
Is anyone here a professional QC person, or a grad student in this field? (Other than Mithrandir) It would be nice if everybody introduces themselves. :) I'm a first year engineering (ECE) undergrad

7:11 PM

Oh yeah :/ The grey blends in to the background on my screen :/
@Blue This sums up all I know about QC:
in The Nineteenth Byte, 1 hour ago, by caird coinheringaahing
Annoyingly, I want to ask a question, but I don't have anything to ask, and joined the proposal mainly because I find it interesting, but not something I'd ask about :/

@Blue I am just an 8-th grader so no expert here :)

Anonymous
@cairdcoinheringaahing Cool :P

Anonymous
@Mr.Xcoder Yeah, we have spoken before, on hbar

Anonymous
Hehe

7:13 PM
Oh yeah you changed your profile pic...
I liked Schrödinger :) But I like this one too

Anonymous
Thanks

Anonymous
Room name we need...hmm...

I just came up with an awesome pun for the room name but I'm concerned it's not on-topic enough

what is it?
also welcome @Blue

Schrödinger's chat

7:17 PM
aboslutely +1 post that plz

0

Schrödinger's Chat A pun on Schrödinger's Cat. It has more to do with Quantum Mechanics in general than just Quantum Computing, but I wanted to throw it out there.

@Blue mith is a gosh darned high school student he's not a professional or grad student

ninja'd

lol

@Mr.Xcoder haha, and chat means cat in french

7:18 PM
+1 that's a great name

@Blue oh, you were the guy with the blue ring icon?

Anonymous
@Pavel It's good, but we already had the same name suggested a few times for the physics SE site's chat

Anonymous
Not very original

Anonymous
@Riker @Mithrandir24601 is a PhD student in QC

@Blue Aww

7:19 PM
My intro: I'm a quantum engineering PhD student and my PhD is to do with simulating open systems, PT-symmetric systems etc on a photonic chip, although I've got a variety of other interests relating to QC
2

oh
wrong mithrandir lol

Anonymous
@Riker Blue ring? I don't remember. Probably not

I thought you were talking about hte other one who's on many private betas

@Riker People always do that :P It's quite funny

Mithrandir ♦, Tauremornalómë
7.3k 5 31 77
but hey cool nice to meet you @Mithrandir24601

7:20 PM
@Riker Good to meet you too :) I plan on spending much time here :)

Anonymous
In case you guys didn't notice we also have Daniel Sank, who is a member of Google Quantum AI group, on this site

^ i noticed that

Anonymous
I hope this site will gather more experts as time goes on

@Blue We've actually got a few academic QC people around/committed to the proposal, although I don't see any in chat currently

Anonymous
As for me, I'm a first year undergrad who has been learning the basics of QC from various online sources and textbooks for my internship this summer. Hope to learn a lot from the members on this site. :)

7:23 PM
lol I hope so too

Anonymous
@Mithrandir24601 Yep. For example:

Anonymous
Bjørn Kjos-Hanssen, University of Hawaii
141 4

Anonymous
@GypsySpellweaver \o

@GypsySpellweaver o/ welcome

7:26 PM
@Blue He's very active on MathOverflow, he's definitely a mathematician

Anonymous
@Riker So, uh, you didn't introduce yourself yet? ;)

Anonymous
I see you're a mod

@cairdcoinheringaahing QC is part of CS, physics, maths and engineering though, so you can still be any of those while being a 'QC person'

@Blue random high school kid from CA, USA who likes math

@Mithrandir24601 Yeah, I was referring to Blue's (now deleted) message

7:29 PM
happen to be vegetarian/mod on veg.se

Anonymous
@Riker Oh, awesome. Lots of young blood in here :D

@cairdcoinheringaahing Aaahhh, fair. Fair :P

To be completely honest, quantum physics breaks my brain, so I expect I'll end up being a user with 101 rep in 6 years time, when this site really takes off :P

accepted edits give you +2 rep :)

Anonymous
There are a lot of rumors regarding quantum physics, but I really think if you are learning from the right material it's much simpler than what you would expect.

7:32 PM
I hope to gain rep from .NET knowledge when people ask about Q# rather than actual quantum computing knowledge

Anonymous
@Pavel Lol

remember y'all, upvote all the good things
helps people get ot things like 350 rep to review things

Anonymous
The Q# tag already got created

me and jknappen are pretty close atm

Anonymous
Someone has to burnicate it

7:33 PM
should be auto-done when somebody removes it

Anonymous
@Riker Right

@Riker resembles Dennis and Martin back in the day imo... You just need a couple of more trailing zeroes :P

Anonymous
I will post a few questions and answers on the main site when I get time this week.

Anonymous

Hello!

7:36 PM
@Mr.Xcoder I 'member when dennis celebrated legendary
:p

general discussion

Hmm...Ok

7:39 PM

^
since kritixi coulnd't get a name right
:D

Legendary, thanks!

y'all I ain't seeing any of them updoots
ya better get on it

Huh?

9 mins ago, by Riker
remember y'all, upvote all the good things
9 mins ago, by Riker
helps people get ot things like 350 rep to review things

7:44 PM
Why does the users page only show the top 5?

Anonymous
It's showing all users on my end

Actually I think the 5 on a line meta bug is actually all on a line....
Is this on-topic?

Anonymous

Anonymous
The OP shows no effort at all

Anonymous
1

Is a dilution refrigerator the only way to cool superconducting qubits down to 10 millikelvin? If not, what other methods are there, and why is dilution refrigeration the primary method?

Anonymous
7:54 PM
Good to see technical questions coming up

Hmm, should we set up a feed to post new questions in chat?

Anonymous
Only room owners and moderators can do that. I think it can be done, since the question rate is low as of now.

@Riker is a mod

yes
I can do that

Anonymous
No harm in trying. If the question rate blows up we can think of stopping it.

Anonymous
7:58 PM
As of now it is 1 about question per 30 minutes

Or we can simply set up quick feeds?

I can set one up

Like The H Bar has

Anonymous
@Mr.Xcoder Right. Better idea

7:58 PM
@Mr.Xcoder Quick feeds?

Anonymous
But well the quick feeds don't show the question details

you mean a ticker?
no.

Instead of being sent as messages a popup shows in the top left corner

no no no no no.

Anonymous
@Riker Hmm?

7:59 PM
in The Reading Room, Jan 18 '17 at 22:23, by Rand al'Thor
@BESW Oh, please not the ticker :-(

Yeah, a ticker. Not enough questions are being posted to merit that

Anonymous
Fair enough

greetings

it's annoying af, broken on zooms, and you nede to clear it

8:00 PM
@Mr.Xcoder Hi!

else firefox beeps at me

Anonymous
@Riker Yes, I guess everybody has agreed to that. :)

ok cool

Anonymous
Heather, I feel this might become a list question. Perhaps you could narrow it down? At this time, there probably is a small number of methods (maybe just one), but in the future there might be more, which would mean that more answers would be added... — ItamarG3 2 mins ago

Anonymous
8:01 PM
That's something

Anonymous
We need to figure out how to deal with list questions. Though in this particular case I'm pretty sure the list wouldn't be too long, and would fit in a single one paragraph answer.

Anonymous
Hi @heather

why does my question have so many upvotes
it's not great, go upvote good questions y'all

@Blue yeah, do you think my question is a list question? I'm not sure it is

Anonymous
8:04 PM
@heather Well, in your case the list wouldn't be big i.e. :P

Anonymous
2 mins ago, by Blue
We need to figure out how to deal with list questions. Though in this particular case I'm pretty sure the list wouldn't be too long, and would fit in a single one paragraph answer.

yeah, ItamarG3 was saying in the future though it might be a problem...

Anonymous
@heather Right, that's my point

we have a meta, go post answers/vote :p

I think it should be on-topic.

Anonymous
8:06 PM
list-type question $\neq$ resource-recommendation type

tha'ts not what the meta is about

In this field, resources are constantly updating

answers that pertain to a specific resource will quickly become outdated.
Unless we come up with a strict evaluation process for list questions
There's this eternal thing:
Jeff Atwood on November 23, 2010

Over the last 2.5 years, we’ve identified a few problematic classes of questions that tend to get asked on our sites. Many of these are documented in our standard set of close reasons: exact duplicate, off-topic, subjective and argumentative, not a real question, and too localized.

However, as we launched the great Super User experiment, a new, previously unknown class of problematic questions emerged — the shopping recommendation.

That is, on Super User we began encountering questions like: …

Which offers good grounds

Anonymous

8:08 PM
then write a competing answer :D

Anonymous
We could convert all such questions to community-wiki type

Anonymous

i agree with Blue, but yeah, that q/a is not the same as that with list questions.

I dislike that options.

Anonymous
8:09 PM
Some list questions can add a lot of value to the site

Anonymous
Disallowing all of them wouldn't be very wise

-7

Quantum pairs (if that is the right name) is 2 atoms that are paired together and when you stop one from spinning the other also stops with the same spin. Can you use these pairs to have FTL communication between 2 computers?

7

Similar to the question Could a Turing Machine simulate a quantum computer?: given a 'classical' algorithm, is it always possible to formulate an equivalent algorithm which can be performed on a quantum computer? If yes, is there some kind of procedure we can follow for this? The resulting algori...

-6

The title pretty much sums it up – How are quantum computers different from normal ones? i.e. Do all quantum computers need to be supercooled, whereas normal computers just need fans? and similar. I am aware that these things are documented on other sites too (e.g. Wikipedia), but I think these ...

5

At a very basic level, reading or measuring a qubit forces it to be in one state or the other, so operation of a QC to gain a result collapses the state into one of many possibilities. But as the state of each qubit is probabilistic, surely this means the result can actually be any of those poss...

2

Is a dilution refrigerator the only way to cool superconducting qubits down to 10 millikelvin? If not, what other methods are there, and why is dilution refrigeration the primary method?

nonononono

Anonymous
Oh my goodness

feeds are not a good idea atm

Anonymous
8:10 PM
Stop this feed

kill it

That was so sudden
@Riker thanks :D

Riker has stopped a feed from being posted into this room

@ItamarG3 ideally it wouldn't post like that anymore
its' just catching up

Anonymous
8:11 PM
There's a 15 min time delay approx

Solution: ticker
:P

i will not condone such heresy

Ok why are they so bad?

@Riker I know. Which is why I asked it be removed.

They work pretty well on other SE sites

8:13 PM
Hi! I changed my mind. I've decided to stick around on this website a little bit more...

in about a week (hopefully later) we can add it again. When the explosion stream of questions begins.

@nbro Glad to hear it, hope you find something good to post!

Anonymous
@nbro Welcome

@ItamarG3 I think there will actually be less questions posted.

after a week?

8:14 PM
Yup

When we enter public beta

because that's the plan
that way it won't overwhelm.

Anonymous
Right, I'm expecting that the question rate will fall soon

Anonymous
This is the initial frenzy

People are posting like mad now, so that we have a base of questions when the public arrives

8:15 PM
See conlangs for example. Their activity declined instead of increasing

That decline is the point. It's not exactly good, but we can only have feeds if we don't have 5 questions an hour.
or 5 in 30 mins.
Imagine a feed from 10% StackOverflow.

Wouldn't this question
16

by Turing Machine, I mean this as a theoretical concept, not as a physical machine, in case it's not clear. I know that a TM can theoretically simulate anything, but I don't know whether it could simulate something as fundamentally different as a quantum-based computer. Are there any attempts t...

be more appropriately asked on the theoretical computer science website?

@nbro What's that site?

Anyway, it's definitely specificially about QC, so even if it would also be on topic there it works here.

8:18 PM
(Showing off my knowledge of chat 💪)
(Just kidding :D)

I think we should start defining which type of questions should be asked here...

Anonymous
When this site is launched for public, will it be in beta stage or a mature site?

beta
Supposed to be

Anonymous
@nbro We're already trying to do that on Meta

But due to the sponsorship, I have no Idea

Anonymous
8:19 PM
@ItamarG3 I don't see the Beta label

That's what it's there for after all

Anonymous
I have a few issues with "resource-recommendation" and "list-type", which I will elaborate on, tomorrow

Anonymous
I absolutely don't agree with blocking them completely

Anonymous
Rather deal with them on a case-by-case basis

8:21 PM
19

Thrilled to see this site start. Could we please have math notation (mathjax) enabled? Quantum gates, states and many other things are represented by matrices and vectors. So We'll need it.

Yeah!
I don't want to ask this question because I don't want now to do a little bit more of research. Anyway, it would be nice to have a question regarding the details of the newly announced quantum machine by Google: Bristlecone.

10^8 qubits? unlikely. I sniff something weird. Looking into it

ಠ_ಠ Ataco's userscript got a little in the way there

A few possibly interesting questions may be:
1. How does one evaluate the performance of a quantum computer?
Or, if you prefer to restrict yourselves, you may ask
2. How does Google evaluate the performance of their quantum machines (in particular, Bristlecone)?
Instead of Google, you may choose IBM or D-Wave, maybe separate questions?
3. What do we mean by "performance" of a quantum computer?

8:36 PM
Regarding my most recent meta... Am I too pedantic?

I can't reproduce on my phone

4. How does memory come into play in quantum computers? Is there an equivalent of RAM for QCs?

Are you using Safari?

Anonymous
@Mr.Xcoder It's fine. I'm dying to see more technical questions and answers come up. Mostly I'm seeing pop-sci type stuff as of now.

Same :)

8:38 PM
I'm waiting to see what question will be the first HNQ question :P

@nbro Sure there is. Isn't that literally what Qubits are? Memory?

@Pavel Qubits can be used as memory (if they've got a good coherence time/low loss), but that doesn't mean that all qubits are used as part of memory

I will come up with other questions. Anyway, we, as a community, should discuss possible (canonical) questions here and agree if they are good or not, then ask them! No?

So currently, all Qubits we've made are essentially Level 1 cache

Anonymous
How does <Q|C> chat look, as a room name?

8:45 PM
yes!
wait.

Explain?

Nah

@Pavel I wouldn't go as far as saying all - there have been a good number of 'memory qubits' created - but the majority, certainly

Too hard to type out IMO

maybe Q |0>+C|1>

Anonymous
8:46 PM
@Pavel Just 3 symbols found on any keyboard :P

Eh

I don't get it. What's the reference?

Anonymous
@ItamarG3 That's a bit cryptic, but okay

@cairdcoinheringaahing It's a way to represent qbit states

Anonymous
@cairdcoinheringaahing Q = Quantum C=Computing |Q> is a bra vector notation. <C| is a ket vector notation.

Anonymous
8:48 PM
And yeah, that ^

I've been trying to think of a pun on Hadamard for a while now but I'm just not that good at this sort of thing.

chat-amard?

It has to be a good pun/reference

It also doesn't have to be obviously chat related

are you laughtose intolerant? was that too cheesy?

8:51 PM
Movies.SE has "The Screening Room" for instance

maybe "The Gate"?
or "The QGate"?
I always like chat naming

Can we close this question: quantumcomputing.stackexchange.com/q/26/72? It's simply too broad!

Anonymous
<Q|C> gate

:( There isn't a Unicode character for "qubit"

I don't like these room names with <>

Anonymous
8:55 PM
@nbro It was opened by some moderator

Anonymous

it wasn't opened by a mod

Anonymous
@ItamarG3 ?

I think it was just normally reopened

8:56 PM
Yeah, I VTRO

ಠ_ಠ

Anonymous
Ah, okay

I had so many questions yesterday, but I can't think of a single one

5. How does the concept of "measurement" come into play when building a QC? 5.1. What exactly are we measuring in a quantum computer?, 5.2. How is "measurement" a problem or impediment to building QCs?
These questions may seem basic to someone who's already familiar with QCs, but their answers may serve as canonical answers to the whole community.

But all of those are answered by looking at the wikipedia.
I see 2 alternatives

Anonymous
8:58 PM
I like the idea of some canonical questions and answers like that. It's sometimes difficult for beginners to find the right info from Wikipedia

Either we go ruthless, like Mathematica. Anything already the docs is off topic.

@ItamarG3 Even if that's the case, the format of this website is another, i.e. a Q&A website.

Or we become forgiving, and just point to our own version of docs.
@Blue fair point. Consider my convinced.

Anonymous
Something like JR's canonical answers on Physics SE

Just come up with some questions you think people may have!
Discuss them here. If we all approve them, then we may ask them!!

Anonymous
9:00 PM
But before starting a canonical QA thread discuss here

I support making a reference question, CW, And it'll have all the answers to a list of basic questions.
proposition: sandbox

Anonymous
@ItamarG3 Agreed

@ItamarG3 In what sense?

similar to in meta faqs

We should just strive to create "good" questions and answers...

9:01 PM
@cairdcoinheringaahing a way to make sure that the canonical answers are actually good.

Ah, so for the canonical answers, not for questions in general

Chat room name idea: The Unobservatory
Since you can't observe Qubits or they lose their state

Well, I'm off to watch stranger things.

Anonymous
Cya. I gotta go too

Anyway, I do not think it is a problem if this website grows slowly, provided that the quality of the Q&As are "excellent".

9:05 PM
(observe stranger things -> observe strange things -> observe strange quarks -> observe particles -> what now?)

@nbro What type of QC? A measurement based one, or a circuit-model one? Is the first issue that comes to mind...

Anyway, we may have a chat dedicated to proposals of questions. What do you think?

@nbro They're just 2 different types of architectures - 'measurement based' creates a large state of qubits that are measured bit by bit, with the outcome of each affecting the operations being performed on the others (using feed forward), while 'circuit model' is the one that most people know of, where you start with some initial state and apply unitaries before measuring at the end
@nbro Sounds like a good idea - we could also have a meta sandbox (i.e. a post on meta where people answer with proposed questions)

I disagree with that

@cairdcoinheringaahing OK. Depends what others think of course though :P I have seen it used very well on Worldbuilding SE

9:16 PM
A Q&A site doesn't need a proposed question sandbox, that's what editing is for
@Mithrandir24601 Sorry about the tone of that, it came off all wrong :/

@cairdcoinheringaahing I meant during this initial phase, given that we still don't know exactly which questions are on topic here.

@cairdcoinheringaahing Ah, but the point is that people can suggest much more freely without questions having to get closed/reopened left, right and centre
@cairdcoinheringaahing Nah, you're good :) You're perfectly welcome to disagree

@Mithrandir24601 Yeah, that's a good point!

We have a Sandbox on PPCG, due to the fact that making a good question on that site is way more difficult than on a normal site. I think seeing whether questions would actually need a Sandbox would be a nice course of action e.g. if we get a ton of poorly constructed, poorly worded questions, rather than the odd one, then it would make more sense
Otherwise, it seems too precautionary IMO

@cairdcoinheringaahing Fair. There are a few questions that need a bit of fixing, but I do agree it's early days

9:21 PM
And also there’s this cool feature called “editing” :P

5 mins ago, by caird coinheringaahing
A Q&A site doesn't need a proposed question sandbox, that's what editing is for
Ninaj'd :P

Yeah I don’t think Q&A sites would ever need sandboxing either

2 hours later…
10:53 PM
Are we the only site that has a main design but no chat design

Way too early to know if a sandbox is worth considering yet. If and when users have a consistenly hard time creating questions that are reasonable for the site then a sandbox seems worth discussing on Meta. (Just my twopence worth.)

Yeah. I doubt it'll come to that.

I don't thing it will either. The largest problem I see with this site's questions is the education of new users brought in through the sponsorship that have no SE experience, and lots of experience in various fora and mailing lists.

11:14 PM
Which isn't necessarily a bad thing. A brand new beta site needs all the help it can get.