Quantum-Computing
Two Bit Quantum Computer online
Research Links
Once you understand the simulation you can ask permission to use the real thing. I guess that that will not be necessary because the simulation does the same thing.
Quantum-Computing
Video: Quantum Computation simulations using Mathematica and Free Quantum Computing Add On
This calculations are available at: http://homepage.cem.itesm.mx/lgomez/quantum/v7phase.pdf
Shor's Factoring Algorithm is very important because it showed that a Quantum Computer will be more efficient than a normal computer when solving some important, practical problems (Factorization is important in the secure transmision of electronic data, like credit card numbers). This video shows briefly how Shor's algorithm can be simulated in Mathematica using the free Quantum add-on. Quantum is available at: http://homepage.cem.itesm.mx/lgomez/quantum/
Physics
Video: Erann Gats explanation of quantum entanglement, measurement and interpretations
Using transmissive polarized sheets
Polarizer material experiment @ see 15:00 to 16:00 into the video below
—– 0 deg | —- 90 deg | = nothing comes out.
—– 45 deg | —– 0 deg | —– 90 deg | = ~nothing comes out. I am calling the leakage "0"
—– 0 deg | —– 90 deg | —– 45 deg | = ~nothing comes out.
—– 0 deg | —– 45 deg | —– 90 deg | = 1/4 intensity
1/4 intensity is due to electric field vector being diminished 2 times by square root of 2. Electric field is thus 1/2 and intensity will be the square of this at a value of 1/4.
Later in the talk Garrett uses a polarization rotator. This takes the output of one orthogonal polarizer and spins it 90 degrees so that it aligns with the second polarizer giving no relative loss to a single sheet of polarizer material. A single sheet of course has a loss of 1/2 when fed with unpolarized light. See image below.
David Mermin's "Stuff Left Behind" in terms of Von Neuman entropy.
It is highly recommend you watch David Mermin's "Stuff Left Behind" presentation before you watch this presentation. Mermin's work is like chapter 1 and this is like chapter 2.
Ron Garrett aka Erann Gat quantum video on quantum mechanics. It helps make quantum mechanics more clear by using very accessible experiments that use light as the test subject.
Research Links
- David Mermin's "Stuff Left Behind" presentation
- Erann Gat Website
- Ron-Garret-QM – local copy in case removes PDF version of the presentation done in 2001
- Quantum Eraser Experiment
- Double Slit Quantum Eraser – Walborn et al –
- Wikipedia: Von Neumann Entropy
- Local Copy: Quantum Mechanics of Measurement N. J. Cerf, C. Adami – Original location
- Quantum Entanglement of Photons demonstrated in relatively low cost set up – The presentation included here has simple explaination and experimental setup.
- Boojums All the Way Through is a collection of essays that presents the dilemma of communicating modern physics to both physicists and nonphysicists
- Home Made Quantum Eraser Experiment Using Laser 2 Slits Polarizer Material
- Two Slit Experiment with Quantum Eraser Realized with RF Components
Von Neumann Entropy
Where lambda are eigenvalues of the system. Very similar to Shannon entropy but I suppose with complex values.
Notes
- The polarizer experiments that he shows are quite interesting.
- This presentation builds on David Mermin presentation is like a second chapter to that
- The 3 particle correlation shown near the end is the David Mermin "Stuff Left Behind" presentation
Information-Theory
Quantum Entanglement of Photons demonstrated in relatively low cost set up
- Louis DeBroglie does not get the credit he deserves for original thinking in quantum machanics – DeBroglie thesis paper – he won the Nobel Prize in 1929 for very good reasons which you will see if you read his thesis paper.
- I am looking for the single photon counter used in this experimental setup
PowerPoint presentation of experiment Uses an SPCM-APD ( Single Photon Counting Module – Avalanch Photo Detector )
Relatively simple setup uses spontaneous parametric downconversion of photon to create 2 photons that are entangled. Then these are sent to 2 single photon detectors. If you have any of the parts or pieces of this setup for sale I would be interested in buying.
Physics
Video: KITP Lecture : Putting Weirdness to Work: Quantum Information Science
boxes and soxes
Backup copy: Putting quantum weirdness to work: Quantum Information Science
Quantum physics, information theory, and computer science are among the crowning intellectual achievements of the 20th century. Now, a new synthesis of these themes is underway. The emerg- ing field of quantum information science is providing important insights into fundamental issues at the interface of computation and physical science, and may guide the way to revolutionary technological advances. The quantum laws that govern atoms and other tiny objects differ radically from the classical laws that govern our ordinary experience. In particular, quantum information (information en- coded in a quantum system) has weird properties that contrast sharply with the familiar properties of classical information. Physicists, who for many years have relished this weirdness, have begun to recognize in recent years that we can put the weirdness to work: There are tasks involving the acquisition, transmission, and processing of information that are achievable in principle because Nature is quantum mechanical, but that would be impossible in a less weird classical world. John Preskill will describe the properties of quantum bits ("qubits"), the indivisible units of quantum infor- mation, and explain the essential ways in which qubits differ from classical bits. For one thing, it is impossible to read or copy the state of a qubit without disturbing it. This property is the basis of "quantum cryptography," wherein the privacy of secret information can be founded on principles of fundamental physics. Qubits can be "entangled" with one another. This means that the qubits can exhibit subtle quantum correlations that have no classical analogue; roughly speaking, when two qubits are en- tangled, their joint state is more definite than the state of either qubit by itself. Because of quantum entanglement, a vast amount of classical information would be needed to describe completely the quantum state of just a few hundred qubits. Therefore, a "quantum computer" operating on just a few hundred qubits could perform tasks that ordinary digital computers could not possibly emulate.
Links
[insert page='quantum-mechanics-table-of-contents-toc' display='content']Physics
Video: Spooky Actions At A Distance?: Oppenheimer Lecture – David Mermin – and Rhetorical Homework Problem Solution
David Mermin is great presenter. Emailed him and tried to get him to grade my solution to the homework problem. He did not want to give away the answer and spoil future talks.
Quantum-Computing
Video: The race to Absolute Zero
This is the story of Dewar and Kamerlingh Onnes race to liquify gases. The ultimate challenge was helium. Dewar gavce up after hydrogen as he found it difficult to get helium and had all along gone light on equipment whilst Onnes used a more industrial approach,. Onnes received the Nobel prize for doing this.
The unfortunate thing is that later superconductivity and superfluidity was found by Onnes. Had Dewar persisted he might have found superconductivity and got the prize anyway!
The ultimate acheivement detailed is the creation of an Bose Einstein condensate in 1995.
If you like science / physics this one is for you!
Quantum-Computing
Quantum Computing Video strips down computing mechanics explanation to minimum
Simple is good
The reason why is that the entangle states provides greater enumeration. It is as if the bits are conscience of one another. What this video does is better than others is to strip the wave mechanics out of quantum computing to the extent possible.
Explanations are phrased in terms of red and green balls put in boxes with 2 doors. Put a red ball in a box through door number 1 and if you go back and observe the ball through door number 1 it is always red. If you observe the ball through door number 2 then it is 50-50 odds that you observer red or green.
More explanation after I watch a few times.
Physics
Quantum Mechanics Entanglement and Spooky Action at a distance
Very interesting and experimental approach to entanglement and Bells inequality.
Interesting points of note in the video
- pop bottle bottom glasses on 70's guy!
- Eigenvalues of a quantum mechanical solution are what you can observe. You never observe solutions that are combinations of eigenvalues.
- StarTrek looking test apparatus mock up. Scotty would have felt at home fixing this bugger!
- Einstein did not like ghostly action at a distance. EPR
- Assume quantum theory is incomplete: Look for a hidden variable. Photon pairs are emitted with a shared equal hidden parameter.
- Theories using hidden variables have been created that preserve locality and realism
- Experiments that only test perfect correlations do not force us to choose between quantum explanation and hidden variable method
- John Bell was the first person to show how to bring the two theories into conflict so they could be tested
- Testing perfect correlations are tantamount to looking at one sock and seeing it is blue and concluding the sock on the other foot is blue
- Imperfect correlations: set the target polarizers at unequal angles.
- Alain Aspect and company tested Bell's Theorem
- Tunable lasers were required for this test setup
More …….