https://www.facebook.com/events/187309621424864/?context=create

Imagine a computer more powerful than all the world’s current computers put together. Researchers recently announced the creation of the world’s first quantum bit, the building block that will help us engineer quantum computers capable of solving impossible problems and processing and storing practically infinite amounts of data.

Riff-in-Thyme said:

https://www.facebook.com/events/187309621424864/?context=create

Imagine a computer more powerful than all the world’s current computers put together. Researchers recently announced the creation of the world’s first quantum bit, the building block that will help us engineer quantum computers capable of solving impossible problems and processing and storing practically infinite amounts of data.

(dons the ‘Hat of Pedantry’)

‘Impossible’ problems cannot, by definition, be solved.

‘Nearly impossible’ problems can be solved, as might many ‘apparently impossible’ problems. But, not the impossible ones.

(doffs the ‘Hat of Pedantry’)

Riff-in-Thyme said:

https://www.facebook.com/events/187309621424864/?context=create

Imagine a computer more powerful than all the world’s current computers put together. Researchers recently announced the creation of the world’s first quantum bit, the building block that will help us engineer quantum computers capable of solving impossible problems and processing and storing practically infinite amounts of data.

Nearly infinite data.

captain_spalding said:

Riff-in-Thyme said:

https://www.facebook.com/events/187309621424864/?context=create

Imagine a computer more powerful than all the world’s current computers put together. Researchers recently announced the creation of the world’s first quantum bit, the building block that will help us engineer quantum computers capable of solving impossible problems and processing and storing practically infinite amounts of data.

(dons the ‘Hat of Pedantry’)

‘Impossible’ problems cannot, by definition, be solved.

‘Nearly impossible’ problems can be solved, as might many ‘apparently impossible’ problems. But, not the impossible ones.

(doffs the ‘Hat of Pedantry’)

everyone finished with the ‘Hat of Pedantry’? Does anyone wish to model the ‘Helmet of Conspiracy’?

I</I> didn’t say a word.

:-)

Everything’s nearly infinite.

It’s just that some things are nearer to infinite than others.

http://www.uniken.unsw.edu.au/features/researchers-build-first-quantum-bit-silicon

In 1998, an American postdoctoral researcher at UNSW named Bruce Kane proposed in Nature the idea of implanting a single phosphorus atom into a silicon chip to form a quantum bit – the fundamental component of a quantum computer.

At the time, the notion of being able to harness the curious quantum properties of sub-atomic particles like electrons for the purposes of computing was radical.

But Kane’s vision of using silicon, a material well understood by an expanding computer and electronics industry, opened a new avenue of research into these mythical machines and attracted significant interest from the scientific community.

The paper, which has since generated an extraordinary 2,000-plus citations, soon formed the theoretical launching pad for a multi-million dollar Australian research effort headquartered at UNSW to build a quantum computer.

Fourteen years after this seminal paper was published, a UNSW research team has again cracked the prestigious pages of Nature reporting the realisation of Kane’s vision: the world’s first quantum bit based on a single phosphorus atom in silicon.

Anyone able to pull a paper that explains the bit rather than the exciting possibilities of quantum computing?

Someone has to ask the big question. Does it come in different colours?

Riff-in-Thyme said:

https://www.facebook.com/events/187309621424864/?context=create

Imagine a computer more powerful than all the world’s current computers put together. Researchers recently announced the creation of the world’s first quantum bit, the building block that will help us engineer quantum computers capable of solving impossible problems and processing and storing practically infinite amounts of data.

Huh? Quantum bits (aka qubits) are not new.

A qubit is a quantum superposition of two orthonormal quantum states:

|y> = z₁ |0> + z₂ |1> ; z₁z₁* + z₂z₂* = 1

http://www.technologyreview.com/view/515286/the-phosphorous-atom-quantum-computing-machine/

http://arxiv.org/abs/1305.4481

Boris said:

http://www.technologyreview.com/view/515286/the-phosphorous-atom-quantum-computing-machine/

http://arxiv.org/abs/1305.4481

thank you Boris

KJW said:

A qubit is a quantum superposition of two orthonormal quantum states:

|y> = z₁ |0> + z₂ |1> ; z₁z₁* + z₂z₂* = 1

An n-qubit quantum computer would have n qubits in quantum entanglement. For example, for 2 qubits:

|y> = z₀₀ |0>|0> + z₀₁ |0>|1> + z₁₀ |1>|0> + z₁₁ |1>|1> ; z₀₀z₀₀* + z₀₁z₀₁* + z₁₀z₁₀* + z₁₁z₁₁* = 1

KJW said:

KJW said:

A qubit is a quantum superposition of two orthonormal quantum states:

|y> = z₁ |0> + z₂ |1> ; z₁z₁* + z₂z₂* = 1

An n-qubit quantum computer would have n qubits in quantum entanglement. For example, for 2 qubits:

|y> = z₀₀ |0>|0> + z₀₁ |0>|1> + z₁₀ |1>|0> + z₁₁ |1>|1> ; z₀₀z₀₀* + z₀₁z₀₁* + z₁₀z₁₀* + z₁₁z₁₁* = 1

I appreciate the thought but that is about as clear as mud to me.

Riff-in-Thyme said:

I appreciate the thought but that is about as clear as mud to me.

That’s what a quantum computer is. There is no simpler explanation. One really has to understand quantum mechanics to understand how a quantum computer works.

i just thought they got help from other computers in other universes.

Boris said:

i just thought they got help from other computers in other universes.

In the many-worlds interpretation, that’s one way of looking at it.

KJW said:

Riff-in-Thyme said:

I appreciate the thought but that is about as clear as mud to me.

That’s what a quantum computer is. There is no simpler explanation. One really has to understand quantum mechanics to understand how a quantum computer works.

Perhaps I can give some explanation:

The quantum states |0> and |1>, which can be thought of as unit-length vectors perpendicular to each other, are analogous to the 0-value and 1-value of an ordinary computer bit. But whereas an ordinary computer bit can only have one or the other value, a qubit is a superposition of both values, with a complex number weight value that determines the proportion of each quantum state in the superposition. The sum:

|y> = z₀ |0> + z₁ |1>

is a vector sum so that |y> is also a unit-length vector in the 2-dimensional space spanned by |0> and |1>.

8 qubits would be analogous to an ordinary computer byte. But whereas a byte can have only one value that is between 0 and 255, 8 qubits have all 256 values in quantum superposition with each value having a weight within the superposition.

So any engineering area here will be exponentially more complex than with byte tech?

> Imagine a computer more powerful than all the world’s current computers put together. Researchers recently announced the creation of the world’s first quantum bit, the building block that will help us engineer quantum computers capable of solving impossible problems and processing and storing practically infinite amounts of data.

Please excuse my cynicism here. My age is showing.

My (limited) understanding is that quantum computers are only good for certain specific types of problems, a specific subset of what used to be known as Single Instruction Multiple Data (SIMD) problems. That’s good, but limited; modern computers have moved away from that towards MIMD.

It used to be said that a quantum computer had to be built with hardware that matched the problem to be solved. So in order to solve a specific problem you couldn’t do it in software, only in hardware. That would have greatly limited applications. But I believe that that problem has now been at least partially overcome.

The way “infinite” is thrown around it looks like few people have ever encountered an infinite.

words and phrases that are generally more accurate than infinite;

-lots

-a maximal quantity

-seemingly endless

-more work than I’m willing to commit to

This has probably been discussed previously, but entanglement allows communication greater than c. The fact that it is not the physical transferral of a particle does not necessarily diminish the significance of there being a means to work around the c boundary. What are the current limitations on what can be done with this development?

Quantum mechanics

Certain phenomena in quantum mechanics, such as quantum entanglement, appear to transmit information faster than light. According to the no-communication theorem these phenomena do not allow true communication; they only let two observers in different locations see the same event simultaneously, without any way of controlling what either sees. Wavefunction collapse can be viewed as an epiphenomenon of quantum decoherence, which in turn is nothing more than an effect of the underlying local time evolution of the wavefunction of a system and all of its environment. Since the underlying behaviour doesn’t violate local causality or allow FTL it follows that neither does the additional effect of wavefunction collapse, whether real or apparent.

The uncertainty principle implies that individual photons may travel for short distances at speeds somewhat faster (or slower) than c, even in a vacuum; this possibility must be taken into account when enumerating Feynman diagrams for a particle interaction. It has since been proven that not even a single photon may travel faster than c. In quantum mechanics, virtual particles may travel faster than light, and this phenomenon is related to the fact that static field effects (which are mediated by virtual particles in quantum terms) may travel faster than light (see section on static fields above). However, macroscopically these fluctuations average out, so that photons do travel in straight lines over long (i.e., non-quantum) distances, and they do travel at the speed of light on average. Therefore, this does not imply the possibility of superluminal information transmission.

There have been various reports in the popular press of experiments on faster-than-light transmission in optics—most often in the context of a kind of quantum tunnelling phenomenon. Usually, such reports deal with a phase velocity or group velocity faster than the vacuum velocity of light. However, as stated above, a superluminal phase velocity cannot be used for faster-than-light transmission of information. There has sometimes been confusion concerning the latter point. Additionally a channel that permits such propagation cannot be laid out faster than the speed of light.

Quantum teleportation transmits quantum information at whatever speed is used to transmit the same amount of classical information, likely the speed of light. This quantum information may theoretically be used in ways that classical information can not, such as in quantum computations involving quantum information only available to the recipient.

http://en.wikipedia.org/wiki/Faster-than-light

mollwollfumble said:

My (limited) understanding is that quantum computers are only good for certain specific types of problems, a specific subset of what used to be known as Single Instruction Multiple Data (SIMD) problems. That’s good, but limited; modern computers have moved away from that towards MIMD.

But is SIMD really a limitation? While in practice, the ability to break a problem into smaller parts does make it easier to solve, ultimately any n-qubit state can be transformed into any other n-qubit state with a single unitary transformation. Perhaps the linearity of this transformation is a real limitation, however.

Today, I was thinking about reversibility in ordinary computers, and it occurred to be that a two-bit to two-bit logic gate could be constructed as an element of the permutation group of four objects. There would be 4! = 24 possible gates, though I haven’t worked out if this includes all 16 possible 2-bit truth functions.