CHOMPING AT THE QUBIT IBM announced two new advances to its quantum computing hardware (cooling system and other infrastructure shown): a 20-qubit processor that will be available commercially and a 50-qubit prototype currently undergoing testing
“In quantum computing, a qubit or quantum bit (sometimes qbit) is a unit of quantum information-the quantum analogue of the classical bit.
A qubit is a two-state quantum-mechanical system, such as the polarization of a single photon: here the two states are vertical polarization and horizontal polarization.
In a classical system, a bit would have to be in one state or the other.
However, quantum mechanics allows the qubit to be in a superposition of both states at the same time, a property that is fundamental to quantum computing. ...”
Bit versus qubit:
The bit is the basic unit of information. It is used to represent information by computers.
Regardless of its physical realization, a bit has two possible states typically thought of as 0 and 1, but more generally-and according to applications-interpretable as true and false, or any other dichotomous choice.
An analogy to this is a light switch-its OFF position can be thought of as 0 and its ON position as 1.
A qubit has a few similarities to a classical bit, but is overall very different.
There are two possible outcomes for the measurement of a qubit-usually 0 and 1, like a bit.
The difference is that whereas the state of a bit is either 0 or 1, the state of a qubit can also be a superposition of both.[2]
It is possible to fully encode one bit in one qubit.
However, a qubit can hold even more information, e.g. up to two bits using superdense coding.
For a system of n components, a complete description of its state in classical physics requires only n bits, whereas in quantum physics it requires 2n-1 complex numbers.[3]...”
https://en.wikipedia.org/wiki/Qubit
Thou shalt build with silicon a computer of 22 qubits.
Can it run Windows 10?
Multi-state bit representation was proposed decades ago. It goes like this:
- 0 = No
- 1 = Yes
- 2 = Who Cares
WordStar will scream with this one.
Bfl
Jennifer Ouellette
Nov 7, 2016
The mere mention of “quantum consciousness” makes most physicists cringe, as the phrase seems to evoke the vague, insipid musings of a New Age guru. But if a new hypothesis proves to be correct, quantum effects might indeed play some role in human cognition.
Matthew Fisher, a physicist at the University of California, Santa Barbara, raised eyebrows late last year when he published a paper in Annals of Physics proposing that the nuclear spins of phosphorus atoms could serve as rudimentary “qubits” in the brain—which would essentially enable the brain to function like a quantum computer.
As recently as 10 years ago, Fisher’s hypothesis would have been dismissed by many as nonsense. Physicists have been burned by this sort of thing before, most notably in 1989, when Roger Penrose proposed that mysterious protein structures called “microtubules” played a role in human consciousness by exploiting quantum effects. Few researchers believe such a hypothesis plausible. Patricia Churchland, a neurophilosopher at the University of California, San Diego, memorably opined that one might as well invoke “pixie dust in the synapses” to explain human cognition.
Fisher’s hypothesis faces the same daunting obstacle that has plagued microtubules: a phenomenon called quantum decoherence. To build an operating quantum computer, you need to connect qubits—quantum bits of information—in a process called entanglement. But entangled qubits exist in a fragile state. They must be carefully shielded from any noise in the surrounding environment. Just one photon bumping into your qubit would be enough to make the entire system “decohere,” destroying the entanglement and wiping out the quantum properties of the system. It’s challenging enough to do quantum processing in a carefully controlled laboratory environment, never mind the warm, wet, complicated mess that is human biology, where maintaining coherence for sufficiently long periods of time is well nigh impossible.
Over the past decade, however, growing evidence suggests that certain biological systems might employ quantum mechanics. In photosynthesis, for example, quantum effects help plants turn sunlight into fuel. Scientists have also proposed that migratory birds have a “quantum compass” enabling them to exploit Earth’s magnetic fields for navigation, or that the human sense of smell could be rooted in quantum mechanics.
Fisher’s notion of quantum processing in the brain broadly fits into this emerging field of quantum biology. Call it quantum neuroscience. He has developed a complicated hypothesis, incorporating nuclear and quantum physics, organic chemistry, neuroscience and biology.
While his ideas have met with plenty of justifiable skepticism, some researchers are starting to pay attention. “Those who read his paper (as I hope many will) are bound to conclude: This old guy’s not so crazy,” wrote John Preskill, a physicist at the California Institute of Technology, after Fisher gave a talk there. “He may be on to something. At least he’s raising some very interesting questions.”
Senthil Todadri, a physicist at the Massachusetts Institute of Technology and Fisher’s longtime friend and colleague, is skeptical, but he thinks that Fisher has rephrased the central question—is quantum processing happening in the brain?—in such a way that it lays out a road map to test the hypothesis rigorously. “The general assumption has been that of course there is no quantum information processing that’s possible in the brain,” Todadri said. “He makes the case that there’s precisely one loophole. So the next step is to see if that loophole can be closed.” Indeed, Fisher has begun to bring together a team to do laboratory tests to answer this question once and for all.
https://www.theatlantic.com/science/archive/2016/11/quantum-brain/506768/
DWAVE is building quantum computers with multiple thousands of qubits, and has been for several years. Why is this news?