Main Topics from : A Shortcut Through Time

Supercomputers

Traditional Computing Bit – holds a binary digit of 1 or 0. All the parts are made of more than one atom

Quantum computer Uses single atoms Holds 0, 1, or 0 and 1 These types of computer s are special because they can store 2^x different numbers where x is the number of atoms. The drive for wanting these types of computers is that they can test all the different numbers from input or output simultaneously With this type of computer they plan to solve large factoring problems, this would decrease security( covered in a later slide) They would also require And and Not gates. These gates have been proven as plausible by people like Cirac and Zoller. You can not check the digits that are being held until the end otherwise the atoms holding a 0 and 1 will randomly become a 1 or 0.

Making a Computer

The atom and Quantum Computing Atoms can spin up(counterclockwise) Atoms can spin down(clockwise) Atoms can also spin up and down simultaneously Because of this they are perfect for use in quantum computing, they can be effected by lasers and set up to effect each other. By having the atoms effect one another you are able to actually “program” how you want the information to change.

Security Problems caused by Quantum Computers According to Shor’s algorithm, a quantum computer could be used to break extremely large numbers into their primes, something that would previously could take millions of years. The problem with being able to speedily factor large numbers is that most of the encrypted information has been influenced by the prime of a number a company picked, this number is publicly available.

Different approaches to making a Quantum Computer Cavity QED – uses photons NMR – uses molecules, causing the nuclei to spin to represent 0, 1, and 0 and 1.

Checking your information Many errors occur through quantum computing as the atoms get affected by their environment and are no longer both 0 and 1. To fix errors many different approaches have been taken, like adding a 0 if the number of 1s is even and adding a 1 if the number is odd, or by using multiple atoms to store the same bit so that they will all say 1 displaying 1111 so that you know if one is incorrect. The most used way is to add 3 atoms after every four with the rule where the atoms have 1 for odd number of 1s or 0 for even number and the 3 atoms cover the 4 by having the first cover atoms 1,2,3 the second cover 2,3,4 and the third cover 1,2,4.

Encoding data With quantum computers causing data to no longer be safely protected in its current form new way of encoding it needs to be made. The current idea of how to do this uses protons. One proton at a time is sent through a line to the other side with someone on both sides of the line. The person on the sending side randomly turns a block vertically and horizontally and so does the person on the other end. When the person on the other ends scanner reads the proton they write how they were holding the block and the direction the proton was spinning. If it was - / it was 0 if it was I \ it was 1. Then they call each other and the receiver says which way they were holding the block. They keep the data for the points where they both held the block the same way and discard the rest. They can check their data by selecting a small portion of it and comparing. This compared portion is then discarded. Then the binary made from the 1s and 0s is the number that is their new key.