Category Archives: Quantum Physics

The vision for the global quantum internet

Originally posted on the Cambridge University Press blog Fifteeneightyfour. The book “The Quantum Internet: The Second Quantum Revolution” is available for purchase here along with a free online preview.

The true power of classical computing was never fully realised until the emergence of the internet, enabling the global integration of computing infrastructure. Indeed, many of our present-day devices would have very little utility without it. In the absence of the internet, consumers would not be able to rely on cloud infrastructure, information sharing and communication would not be possible, supercomputing would be largely inaccessible, and smartphones would be little more than bricks. The internet enables information to be a commodity whose market value drives technological advancement.

With emerging quantum technologies the quantum internet will be very different and far more powerful. Quantum computers operate according to entirely different principles in the way they process information, which in the future will enable many advanced and extremely economically valuable forms of computation to be implemented which cannot be realised on conventional computers. This raises the immediate question “what if we start networking them together?”

The classical internet is not capable of integrating remote quantum devices. This requires entirely new infrastructure that distributes quantum entanglement, a uniquely quantum information resource. The long-term vision for this infrastructure is the quantum internet, something that will likely develop in the coming decades. As with the emergence of the classical internet, it is to be expected that quantum computers will not realise their full potential until this infrastructure exists. But the motivation is even stronger than for classical devices. When classical computers are unified via distributed cloud-based architectures, the net computational power is effectively the sum of the parts. However, quantum computers exhibit fundamentally different scaling characteristics: a classical computer’s power is roughly proportionate to the number of CPUs it contains, whereas a quantum computer’s power grows exponentially with the number of quantum bits —or qubits— it processes. Therefore, upon unifying quantum devices via a quantum internet, we are left with something far greater than the sum of the parts, acting as an immediate incentive for global cooperation.

This quantum enhancement in computing power translates to enhanced economic incentives and returns, making quantum entanglement a highly valuable future commodity. As with any fungible commodity, entanglement will have a market value that drives economic investment into the infrastructure required to distribute it. In an ideal world, a unified global marketplace would emerge, similar to what we see in other global markets. The strategic implications of quantum computing are immense — breaking important cryptographic codes, making new unbreakable ones, with major implications for research & development, important optimisation problems, drug design and simulation. However, these strategic implications may also fracture quantum networks along geo-strategic boundaries, leading to quantum alliances, diplomacy and politics.

Although it is too early to predict exactly how the quantum internet will evolve over the coming decades, it’s clear this technology will underpin the future quantum era in the same way that the classical internet underpins the present digital era. One thing is certain — the global impact of the quantum internet will be enormous.

An outlook for how a global quantum ecosystem enabled by the quantum internet could emerge.



Introducing QuNet: A quantum internet simulator using cost-vector analysis

We’re pleased to announce our quantum network simulator QuNet, written by my PhD student Hudson Leone.

The Julia source code and documentation are available on GitHub here.

The development of QuNet is based on the theoretical work performed in conjunction with Hudson Leone, Nathaniel Miller, Deepesh Singh, Nathan Langford and myself, presented in our recent arXiv paper “QuNet: Cost vector analysis & multi-path entanglement routing in quantum networks” here.

Here’s the condensed Twitter-thread version:

Jonathan Dowling (1955-2020)

Hi Jon,

Upon coming back online in the midst of camping — wondering which irritating telemarketing firm was pestering me with 27 missed calls and messages — I was completely devastated to learn that one of my closest friends (in our own weird, highly neuro-atypical kinda way), collaborators and mentors — both in academia and in life — Prof Jonathan Dowling, had unexpectedly passed away, whose impact on the world of physics, quantum technology in particular, but most of all upon those with whom he worked — and touched — has been profound. His passing has sent shockwaves through the international scientific community. Jon was, and will remain, one of the most influential people in my life. I know many others can say the same.

Originally I was planning to stay in the camp today, but upon learning this news, instead climbed a nearby peak to erect the most appropriate tribute to Jon I could improvise at the time. Behind the empty bottle of gin (my apologies Jon, the whiskey was still half-full), you will see the Siding Spring Observatory on a nearby mountaintop, which I hope tonight will see a new star in the sky, as he and George Floyd look down from above, both incredibly proud of the American economy*.

*Quick tangent for context: the previous day a woman camping with her son emerged from their tent, saying “My god, did you guys hear that megalomaniac narcissist lunatic wandering around the campsite in pitch black at 5am this morning talking about how good he is, intermittently laughing hysterically? What a complete fucking tool!”. Me: “Oh sorry, that was me and James reading the latest Whitehouse Press interview from CNN. My apologies if you thought you were about to get murdered.” (FYI: she took it pretty well, and saw the humour in it. Not sure about the son.)

The Dowling Tome of the Warrumbungles (geocached at: 31º17’3” S, 148º59’3” E, 760m asl).

Inside the bottle, is a handwritten message, of the most profound and insightful wisdom Jon ever bestowed upon me — of which there is far too much to recall. I geocached the bottle, cunningly hidden away on the summit plateau where it can’t be seen to the naked eye, for someone else to discover (coordinates: 31º17’3” S, 148º59’3” E, 760m asl). I hope one day, one of Dowling’s student-grandchildren — perhaps one of my own — will discover the Dowling Tome of the Warrumbungles, revealing its wisdom for future generations of physicists, and other forms of lunatic, to come. If not, future archeologists will one day uncover it, date it, and ask themselves what primitive species of the distant archeological past would write such incoherent, obviously drunken Irish nonsense.

My friendship and connection with Dowling is a unique one — I think most fond of him can say the same, from their own perspective. Our prisms through which to view the world were so distinct that they provide quite alternate realities within which we respectively live: on one hand highly concentrated from a specific perspective, routine, and way of life, with strict comfort zones and patterns of behaviour; on the other, willy-nilly all over the fucking shop. The fact that such orthogonal lenses through which to view reality, nonetheless demonstrating absolute and respectful recognition for one another — not seeing it as a weakness, but as a strength — is testament to the open-mindedness and inclusivity of both. I think Jon and I would both agree that neuro-diversity is the most important, yet most undervalued form of diversity that exists (it encompasses all the rest).

Jon and I saw the world from opposing ends of the emotional spectrum, yet nonetheless, since the day we met, saw a common underlying sincerity and morality in one another. Every aspect of our world views and life experience were so utterly disparate, yet nonetheless, even at the times of most heightened disagreement, there was always the common thread of utter mutual respect for our differences, the ways in which we viewed the world, and the understanding that an outright difference in opinion should never equate to anger or hate, but rather an opportunity to learn something new. We recognised our differences, of which there were many, not as a basis for exclusion or contempt, rather one most valuable to include for the difference in perspective it has to provide. Jon was one of the few people who has seen me both at my best and at my worst: from hospitalisation to delusion. He never blinked an eye. He accepted it. We would spend all day at the whiteboard, yelling foulmouthed abuse at one another, then switch it off, retire to the pub and piss ourselves laughing about it (unlike the head administrative officer of the host institution at the time, who screamed at us that we were “a bunch of wankers”, before storming off in a hissy fit because we stole the $20k digital whiteboard from the common room that’d she’d previously kicked us out of, something Dowling took utmost amusement in, and wore as yet another one of his badges of honour).

It is this anti-commutation (from the emotional perspective), yet commutation (from that of open-mindedness and inclusivity), that brought us together: this is one thing, regardless of the others, that we agreed upon, despite never having said so — the strongest bonds between us are often those we don’t express. This is the most valuable lesson I have learnt from Jon (but admittedly not the one written inside the geocached bottle of gin) — that alternate views of reality, despite being potentially orthogonal and incongruent, are the most insightful, and should always be accepted, listened to, and heard: alternate realities underpin the discovery of reality, and our different ones underpinned ours. There is no individual on Earth with the intellectual or emotional capacity to single-handedly provide the unified explanation for everything, although many will pretend to. We both recognised this — the value to include all mindsets, despite the fact that one might not be capable of comprehending the other — I could never quite fully grasp his (in fact hardly at all), and he could never fully grasp mine (I don’t think he even tried to, to be honest), yet nonetheless there was an absolute intellectual union between us, at some bizarre level at least. This is the kind of emotio-intellectual union I have had with very few others, and I see it for its value, as should everyone when they encounter it in life. When you lose someone with that level connection, you lose a part of yourself.

To me, Jon was the most inclusive scientist I have ever met, despite being drunk, vulgar and obnoxious much of the time. He never gave a shit about your race, religion, socio-economic class, political orientation, nationality or wealth: his vulgar obnoxiousness was completely and utterly indiscriminate, yet never intended with contempt — all he cared about was whether he believed in you as a person — whether you had the willingness, sincerity and passion to succeed, the only thing that matters, and the one thing we could always agree upon, despite it never being said — in which case you were deserving of more, not less, of his lunacy, which to him was a sign of affection.

Unfortunately his passing means he won’t see our upcoming book, The Quantum Internet, in printed form later this year via Cambridge University Press. He told me it was a pile of crap (referring to it as The Doorstop — because it’s thick and useless), and placed a bet with me (in writing), for a bottle of whiskey of Ryan Mann’s choice (up to a value of $500), that in ten years time it would be my least cited work. He makes these bets with literally everyone, and he always loses. This one was a rookie strategic miscalculation on his part (needles to say, he was completely piss-drunk at the time — not that his reasoning would necessarily be any more coherent if he weren’t), given all I’d need to do to manipulate the outcome of this one is publish a paper gaining no citations at all. “Easy!”, I thought, “I already have plenty of those!”. “You fool, Dowling!”, I smugly boasted to myself at the time, as I went around attempting to win favours from strangers in the form of future contracts by offering them shots of expensive, artisan whiskey, on the tab of one of the world’s most influential physicists, in advance. I was just so proud of myself! On this occasion, however, since he’s a co-author, the book contract is now technically invalidated. I bet the cheeky bastard had it all planned out! God dammit Dowling — was this really necessary, even by our standard of pranksterism (which I acknowledge has significantly devolved to the point of utopia in recent years)? I hope the bottle Ryan had in mind was a bloody good one.

My sense of loss right now is nothing short of catastrophic. But so too is my gratitude for having had a character as unique and impactful as Dowling in my life, which I will continue to despite his passing.

On the last day of his most recent visit here, he made some security arrangements at the last minute, for reasons I can’t go into, on the basis of a presumed threat to his life. His characteristically unfiltered way of explaining his reasoning for that decision (“Peter, I’m still worried he’s going to turn up at one of my lectures with a gun”) triggered a rapid sequence of events that I retrospectively believed saved my own. 

Those larger than life never die, of whom Dowling is one, and are certainly never forgotten. And although my heart is bleeding right now, I know he lives on — not in some bullshit metaphysical sense (the kind of thing he overtly despises, see the Deepak Chopra story below; stay out of it, Keith) — but in the sense that he is one of those who in their lives permanently imparts a sense of themselves onto everyone they touch. This is not something that dies with him, or will ever be lost, rather passed on from one generation of physicists to the next. I’m grateful to have been a recipient of what he had to give, and to use Dowling’s exact words,

“There’s no need to pay it back. Pay it forward instead.”

This is something I hope to do, having recognised what I have gained from my own intellectual forefathers, who I never had the chance to meet, but nonetheless guided me every step of the way.

Wherever you are right now, Jon (hopefully surrounded by a multitude of full, wooden casks), I hope from the bottom of my heart that, as you requested, there’s an Irish cheesecake awaiting you (I think Zixin, Maria & Yuval are sorting that one out) — which I’m assuming is just an ordinary cheesecake with the bottle of expensive whiskey you just cynically conned out of me, poured over the top of it (in which case you’re still not getting it for ten years, so there).

Dowling stories are de facto mandatory at this point. Here are a couple of lesser known ones.

I don’t know why I’m getting all these emails but I sure wish I wasn’t. On travel with only access on my smart phone and they are eating up my data plan.

Deepak Chopra:
it may may be important to remember that no one knows how or if photons hitting the retina and sending an electrical current to the brain create the experience of a 3 D world appearing to evolve in time.
The only light there is is the light of awareness that makes the formless appear as form with color shape dimensionality .

[Editor’s note: Deepak what the fuck is ‘color shape dimensionality’? Seriously dude, do you need an MRI?]

There once was a man from Nantucket.
Who kept all his cash in a bucket.
His daughter (named Nan),
Ran away with a man,
And as for the bucket –– Nantucket!

[Editor’s note: nice.]

Time is a concept
No matter how hard you try you cannot experience a past or future.
Experience is always now

[Editor’s note: thanks for that, Deepak. Please use punctuation in future attempts to use a three line paragraph to explain the otherwise simple notion of “now is now”.]

There once was a lady named Alice,
Who used a dynamite stick as a phallus.
They found her vagina, in North Carolina,
And bits of her tits were in Dallas.

[Editor’s note: in the field of quantum information theory, a two-party interactive protocol typically denotes the parties as ‘Alice’ and ‘Bob’, following the first two letters of the alphabet (yes, you’re correct in thinking that as we extend to multi-party scenarios that we introduce C=Charlie, D=Dickhead, E=Eve, etc etc.). Evidently, Alice’s decision to deploy dynamite may suggest Bob was facing some serious personal issues at the time, which undermined ordinary implementation of the two-party interactive protocol.]

Deepak Chopra:
You know neural correlates of experience . No one knows how the brain or any physical matter causes experience ? The biological basis of experience or consciousness is unknown ( hard problem )

[Editor’s note: no I don’t. I have literally no idea what you’re fucking talking about, Deepak.]

Some other physics wannabe:
I would argue that the 3-D world discovered by the brain is not due to one retina hitting photons but two… If only with one, you would only perceive 2-D…

[Editor’s note: ok so I’m feeling vindicated right now in my usage of the term ‘wannabe’.]

Jack Sarfatti:
You sound like a clueless New Age lite weight.
I hope I am wrong.
Have a nice day.
These days it’s important to be able to filter out reliable information on the web.
The wheat from the chaff.

[Editor’s note: oooooh! Sarfatti comes in with burn of the century. Ouch, that’s gotta hurt. <the wannabe crawls into a corner, devastated that they can’t be as awesome a scientist as Jack – it’s not that they didn’t do the hard work, they just weren’t born with the natural intellect that Jack has>]

There once was a moron named Jack,
Who’s pronouncements were totally whack.
The lab of his mind,
Produced nonsense in kind,
Like smoking some unaltered crack.

[Editor’s note: Jack, is there any crack leftover?]

Deepak Chopra:
They are experiencing memories and emotions from the past not the past
The past does not exist
Reality is free of memory and imagination and is always now

[Editor’s note: there will be no more editor’s notes from now on, since I simply can’t be fucked with this anymore.]

Some other highly ranked professor I don’t know:

[Editor’s note: backtrack one step. I agree. Carry on.]

Yet someone else:
please unsubscribe me from this thread.
I’ll simply conclude by saying that a block world is a possible ontology for physics but not the only possible ontology. Those of you who like the block world can keep it, just don’t tell me that no other ontology is possible 😉

Deepak Chopra:
Correlates of experience (NCC )
The biological basis if any of consciousness or experience is unknown
It’s the 2nd most open question in science
The first open question in Science is “what’s the universe made of ? “
We neither know the nature of existence nor why or how we are aware of it

[Editor’s note: watch this.]

Some random dude:
By the way, I think you’re a pretty bright fellow. Too bright to be making sweeping pronouncements regarding everyone else’s knowledge state. If you simply can’t resist them, might I suggest that you at least hedge them a little? E.g., you might try prefacing them with “As far as I know,” or “To the best of my knowledge,” or “My personal buddies in the publishing industry are laboring under the unfounded assumption that…”.

Another random dude:
Without our minor misunderstanding based upon basic science and biology, how can we obtain consciousness to go to the far abroad in space?

Deepak Chopra:
The brain does not observe
That’s an assumption
That assumption is the basis of the “hard problem” The observer is dimensionless / nonlocal with a local point of view . The observed is also dimensionless but taking on the qualities of experience or qualia .
The infinite observes itself as the finite .
Past future and present are concepts as our space time and dimensionality
What we perceive is not what is .

Someone else:

There once was a douche bag named Chopra,
Whose books read like fake Chinese opera.
About quantum mechanics,
He utterly panics,
And pedals his bullshit on Oprah.

[Editor’s note: here’s a rendition of the Dowling interpretation of Chinese opera.]

Someone else completely random:
Deepak’s sentences are easy to comprehend IF you look your own mind. You can then verify his comments. But, I stress, you must look DIRECTLY at your own mind.

[Editor’s note: make sure to do it DIRECTLY.]

Time is never an experience
T=0 always
No one can ever experience the “past ” or “future ” no matter how hard they try .
The only experience consciousness has is an an intermittent stream of sense perceptions, images feelings and thoughts. These are interpreted and conceptualized as space time and matter.
Consciousness is that in which all experience occurs, in which all experience is known & interpreted & out of which all experience is made.
The universe is consciousness

[Editor’s note: Deepak Chopra is cancelled.]

Jack Sarfatti: (sent to the Provost and Chancellor of LSU, and the Dean amongst others, to which there was no reply.)
Who is Jonathan Dowling? Violation of Professional Ethics by Alleged Faculty Member of LSU
If he really is a professor at LSU he is violating professional ethics.
I suspect it is not really him?

[Editor’s note: if you don’t think it’s really him, why would you write directly to the Provost and Chancellor of a major university to find out?]

Jack Sarfatti:
I have deleted Ed May and Jonathan Dowling. BTW on Dowling’s false accusations of illegal drug use as well as printing a pornographic limerick to this thread note
as well as

For the third time, please unsubscribe me from this list.

Jack Sarfatti:
Peter I have removed u several times
I never added u to begin with
Write private emails to those sending mail
Don’t spam the whole list yourself

Writing private emails to everyone on the list creates just as much spam for everyone on the list as writing to everyone on the list via writing to the list, Jack.

Jon “Dundee” Dowling, with his crocodile tooth Akubra hat.

Introducing the Democractic Quantum Bullshit Detector Bullshit

In response to the highly-acclaimed, largely accurate, yet somewhat opaque and authoritarian Quantum Bullshit Detector Twitter account (@BullshitQuantum),

Screen Shot 2020-03-07 at 8.26.04 am.png

I am pleased to introduce the democratised equivalent, the Democratic Quantum Bullshit Detector Bullshit (@QuantumDemocrat), where all bullshit is determined by you, the people, via Twitter polls, expressing your First Amendment quantum rights on what is bullshit and what is not.


Interestingly, the first result (voting still open at the time of writing this), indicates that three quarters of the community has faith in the original authoritarian Quantum Bullshit Detector, determining it to be ‘Not Bullshit’.


Happy bullshitting! And be thankful that you live in a world where we are all free to call bullshit!

Nb: the editor fully acknowledges the meaninglessness of Twitter polls, as was recently confirmed by a Twitter poll. But that is not to say we can’t have fun, provide a platform to hold one another to account, and the polls and comments can’t trigger useful dialogue, which I very much encourage.