A Quantum of Similarity

By johnnedwill

I first met Doctor Prakash at the Daresbury laboratories in Cheshire. She was devoted to her test rigs and her experiments. At the time we met, the doctor was working on the development of a practical quantum computer. I was more of a theoretical scientist. My area of research was trying to find a solution to the Einstein-Podolsky-Rosen paradox - at least a solution that would make sense at the macro level.

My first encounter with Doctor Prakash was in the cafeteria at Daresbury. Like most of the buildings on site, the cafeteria had been refurbished from an old laboratory block. In the early noughties the university that owned the laboratories had transformed its physics research department into a private technology partnership. The developers had moved in, tearing down the old facilities, erecting new buildings and installing new equipment. The cafeteria was now an open hall filled with tables and bland corporate art. The ticking of radiation counters and the chattering of relays had gone, replaced with the hum of conversation and the clatter of trays.

I was looking for an empty table where I could spread out my papers and eat my lunch in peace. However, the cafeteria was full, with every table occupied by at least one person. So, I looked for the next best thing.

Doctor Prakash was on her own. The table she was sitting at was covered in sheets of printouts arranged in precise rows, each one annotated in her neat handwriting. A tray laden with dirty dishes had been put on one of the nearby empty chairs.

"Do you mind if I join you?" I asked her.

The doctor looked up from her lunchtime studies. "Go ahead." She shifted some of her papers, making room for me to put my lunch tray down.

I glanced at the printouts out of curiosity. The equations on them were familiar. "It looks like you're working on quantum entanglement," I remarked.

Doctor Prakash shook her head. "Not quite. I'm working on possible practical applications. Quantum cryptography, computing, that sort of thing. Entanglement is just one avenue."

I sat down. "I'm Vincent. Martin Vincent. I work in theoretical physics. Very theoretical physics."

"Doctor Anoushka Prakash." She shuffled her papers into a tidy stack. "Just how theoretical?"

"Very. Einstein-Podolsky-Rosen."

The doctor raised her eyebrows at me. "I thought that had been solved?"

"Only for specific cases. I'm hoping to make a breakthrough - the equivalent of going from Special Relativity to General Relativity."

"Really?" Doctor Prakash's tone changed, betraying her growing interest. "'General' as in 'more suitable for practical applications'?"

"That's where the funding is."

And that was how our partnership began.

At first we met in the cafeteria, exchanging ideas over lunch and coffee. Then, as we got to know our work - and each other - better, we began to solidify the areas that were of mutual interest and benefit. After that, it was just a short step to a joint project.

It was a simple proposal. We would develop a means of creating particles linked by quantum entanglement - particles that could be used to form logic gates. These logic gates would then form the core of a quantum processor. And from that? The grant proposal painted a picture of wealth and patents. At the time, 'quantum computing' was the big buzz word. It was meant to the solution to every problem. Lots of money had been invested in it. Projects that were not even halfway feasible were having millions thrown at them on the off-chance that they would lead to something. Our proposal was grounded in proper research, and the canny investors could tell. A month after submitting our paperwork we had enough money promised to us to support a research team of maybe a dozen for the next three years.

We didn't waste any time. Doctor Prakash and I had already been talking to specialist equipment manufacturers and interviewing candidates for roles in our new team. The core of the team would be assistants and and researchers that had been involved in some of our previous projects. We spent another two months sorting out our workspace in the Daresbury laboratories, and then we got down to the task in hand.

The problems with quantum computing were linked to the natures of the raw materials. Quantum computers relied on qubits - particles that had been entangled on a quantum level. The Einstein-Podolsky-Rosen paper posited quantum entanglement as one of the possible solutions to one of the paradoxes it discussed. However, that had been rejected as a solution for many years. Spooky-action-at-a-distance was considered to be too much of a violation of the accepted laws of physics. However, like so many other things associated with quantum mechanics, what seemed impossible became necessary, and what was necessary became reality. The first entangled particles to be produced were a pair of photons. They proved that the Einstein-Podolosky-Rosen paradox was not really a paradox. After that, it was a race to find applications that could take advantage of this phenomenon.

Unfortunately, this was not as easy as it seemed at first. Practical applications needed entangled particles that were more massive and easier to handle than mere photons. Atoms, molecules, even entire macrostructures would have to be linked as quantum twins. While it was relatively simple to entangle photons - all you needed was a coherent light source and a diffraction grating - larger particles needed higher energies and more complex processes. Providing entangled particles in the numbers required by the engineers was described as 'impossible'. However, as with so many things associated with quantum mechanics, the necessity became the reality.

When I met Doctor Prakash, I had been investigating one of the mathematical outliers of the paradox. It suggested that entanglement could be made sticky, allowing one particle to draw another into an ever-growing quantum chain. If it worked, it would only be necessary to entangle two particles. Then, by introducing other particles, the entanglement would spread to those particles, and so on. Despite its promise, there was very little interest in this. The mathematics supporting it were conjectural, and there were more profitable avenues to be explored.

Prakash, on the other hand, had been working on a new application for quantum computing - one that had the money men very interested. That interest had evaporated like so much quantum foam when she presented them with an estimate of how much it would cost to manufacture the necessary qubits. There were hard limits to her backers' generosity. However, our partnership rekindled interest in Doctor Prakash's work. If my 'sticky entanglement' theory could be shown to work, then it would be trivial to make the qubits she needed.

So, six months after getting our funding, the team was gathered in the control room for the Daresbury particle accelerator. Our test sample had been placed just-so in the target chamber. The particle accelerator had been brought up to its full voltage. All that remained was to remove the shield plate that blocked the emissions from the beam line and allow the stream of relativistic particles to hit our sample.

"Five. Four. Three." The technician running the accelerator counted down the seconds. Doctor Prakash and I stared at a monitor that showed us what was going on in the target chamber.

"Two. One. Shield open."

The image on the monitor whited out, the camera electronics momentarily overwhelmed by the radiation flux. The screen slowly returned to normal, and we pressed close to it, eager to see what had happened to our sample.

Our container was in the middle of the target chamber. It was a transparent sphere, five millimetres in diameter, that held our sample. We had decided on a simple means of measuring our success. The target material had been selected to decay after it had been exposed to the particle beam. The decay would show up on the monitor as a red glow. If the theory of sticky entanglement - my theory! - was correct, we would see the red glow spread throughout the material in the container.

Together we watched the monitor screen; watched the material in the container transform, decay and give off its red photons. At first it was just grey with pinpoints of red. But the glow spread, becoming a vivid scarlet, then van fishing as the last of the particles became entangled and decayed.

Doctor Prakash had been timing the progression of the change. "How much material did we have in the beam line?"

"About a hundred microgrammes," I told her.

"I see." Prakash did a quick calculation, scribbling figures on a pad of graph paper and tapping numbers into an old scientific calculator. "That many moles. That long for the decay process. Assume the entanglement spreads at this rate." The doctor tapped her pen on the paper and smiled. "One per cent. We achieved a net stickiness of one per cent."

And that was it.

If this had been a normal research project, we would have immediately written a paper describing our findings. Our backers, however, had asked us to withhold publication of our results until they gave their permission. This was to give them enough time to patent our process, develop it and monetise whatever they could. Of course we would be allowed to publish. Eventually. But, as principles of nature and laws of physics aren't patentable, our backers wanted to be as far ahead of the competition as they could. We had no objections. It wasn't an unusual arrangement for Daresbury.

Having reported our success, we moved onto the next stage of our project. It took nine months to work out and implement a means of scaling-up our production of qubits so we had enough to make our logic gates. Then we had to build the logic gates into an architecture suitable for a processor. All through this, our backers kept demanding regular updates, meetings and justifications for our spending. But, even with all these interruptions, we had our prototype quantum computer.

Next was to put our creation through its paces and prove it would work as we had predicted. This was Doctor Prakash's area of expertise. While she concentrated on this, I was busy addressing some issues with our production process. So, I was surprised when Doctor Prakash came to see me.

"We have a problem with the qubit processors."

I was nonplussed at this news. "Sounds like a hardware problem to me. Not a physics problem."

Prakash cleared a space on my desk and laid out some printed pages. "Take a look and tell me what you think."

I stared at the figures in front of me, but they made very little sense. The only thing that stood out was a number of lines that Prakash had highlighted in red. I pointed at them "I take it these are your problem?"

"Yes."

"Could you explain it to me?"

Doctor Prakash pulled up a chair.

According to her, the processing units in the quantum computer were acting as if there was some kind of interference. They were outputting anomalous, seemingly random results. It was as if the qubits were not properly entangled, or had become entangled with something else.

I was sceptical. Of course, we had anticipated that the qubit processors would become entangled with the materials that they would come in contact with. After all, that was the nature of the sticky entanglement. So we had developed a means of isolating the qubits by magnetically levitating them in a vacuum. If we had to physically manipulate the qubits, everything they came into contact with was subjected to a pulse of deciphering radiation to remove the entanglement. We had instituted level four clean protocols throughout the process. However, the results tat Doctor Prakash were showing me were indisputable. There was some kind of quantum interference in our processors.

A solution had to be found. We split our efforts. Prakash and her team would look at the hardware side to see if there was any possibility they had overlooked in the processor architecture. Meanwhile, my team would check the mathematics underlying the production process and the use of the qubits. We hoped we could find an answer before our backers became nervous. In the end, it was my team - the mathematicians and theoretical physicists - that found the answer. I called a meeting with Doctor Prakash.

"It's bad," I told her.

"How bad?" The doctor looked worried. "Will it delay the project? How long? Can we recover?"

I ignored her questions and pressed on. "The qubits are suffering from interference on a quantum level, and there is nothing we can do about it. They are receiving information from some source we haven't accounted for."

"What other source? How?"

"You are of course familiar with the phenomenon of quantum tunnelling?" 

Doctor Prakash nodded, so I carried on. "Our production process takes advantage of the sticky entanglement. But, because our logic gates are macro-scale quantum structures, they are also capable of quantum tunnelling. They - or the particles that make them up - have managed to become entangled with other particles through quantum tunnelling. So, our entanglement has spread."

Doctor Prakash thought for a moment. "Can we finds these other particles?"

"No. Quantum tunnelling is a random process, influenced by energy bands in a structure. There is no way of knowing what our qubits are entangled with, let alone where they are."

"Alright." The doctor took a deep breath. "So we decoder our qubits,. discard the logic gates and start again. It's bad, but it's not a showstopper."

"That is a possibility. But," and now it was my turn to take a deep breath, "while that might deal with our qubit gates, what about the particles they have become entangled with? If they aren't affected by the deciphering radiation, then they will go on to entangle other particles. And if they do decohere, remember that the entangled particles will emit radiation as they do so. And I have no idea what will happen then."

"Third option?" Doctor Prakash looked at me. "What if we do nothing?"

I shrugged. "I have no idea. Maybe the entanglement process will stop naturally. Maybe it will keep going until all matter in the universe has become entangled."

"which will mean everywhere in the universe - perhaps all possible universe - will be identical at a quantum level."

"Worst case."

"I need to ... ." Doctor Prakash stood up. "We need to think about this."

I nodded. "It's not simple. We need to tell others. Scientists. Politicians. Hell - anyone who will listen! That's how bad this thing might be."

"Yes." Doctor Prakash sat in silence. Then: "Let's make a list of who is going to be easiest to convince. Then we'll meet again. Tomorrow?"

"Tomorrow."

That night, Doctor Prakash - Anoushka - committed suicide. Within days our backers had come in and stripped the laboratories, reclaiming the equipment and seizing our notes. The project was shut down.

I tried to talk to people, to spread the word about the possible dangers our work had unleashed. Unfortunately, the secrecy our backers had insisted on worked against me. As we hadn't been allowed to publish and the project records had vanished, there was no evidence of what we had done. No-one would take me seriously.

In order to find something to give me some credence, I started looking for strange phenomena, coincidences that could only be explained by quantum entanglement. Within months my reputation (such as it was) has been reduced. I was regarded as a maverick, a doomsayer, a crank!

To satisfy a morbid curiosity, I calculated how long it would be until every particle everywhere was brought into the entanglement I had created. However, there was not enough data to come up with a meaningful solution. Either there was too little time to do anything, or there was too much time for people to care about.

So, now I contemplate what to do next. Should I follow Doctor Prakash into the uncertainty of oblivion? Or should I embrace the possibilities of the boundaries of my equations and see what time will bring? Like all things quantum, the impossible will be necessary, and the necessary will be reality.