1. QUANTUM COMPUTERS, COMPUTING AND INFORMATION ALAN DURNEV, PHYSICS

2. INTRODUCTION “If you think you understand quantum mechanics, you don't understand quantum mechanics.” Richard Feynman

3. THE IDEA WAS BORN The idea of quantum computing was first introduced by Yuri Manin ( Russian mathematician) in 1980 and Richard Feynman ( American theoretical physicist) in 1982.

4. BEFORE GOING DEEPER Computers, computing? 1.Individual or society have a problem to solve 2.It is solvable with a computer 3.The set of strict instructions is given = (also known as ) algorithm 4.It is being disassembled into the binary, which is understood by a CPU (formally computer).

5. Binary is a combination of 0 and 1 numbers (mathematically), but theoretically: 0 and 1 = two different states of situation (flip-flop, off-on, closed-opened, switch down-switch up, false-true, “–”-“+”)

7. A gate is a representation of 1(up) and 0 (down) itself! And light bulb – is an end product of a combination of those switches (101) (we can perform different operations). 6. CPU GETs, ADDs, COMPAREs, JUMPS between, JUMPS IF, STOREs(in RAM),LOADs combinations of numbers 1 and 0 7. Result of combination of a binary product is being assembled 8. Result goes to the output device (screen)

8. SUCH AS… ALAN TURING’s MACHINE (abstraction) CHECK, MOVE LEFT, MOVE RIGHT, ERASE, PUT, MOVE TO START POSITION THIS IS THE LOGIC!

9. THE QUANTUM COMPUTING A quantum computer is a computation system that uses directly quantum- mechanical phenomena (superposition, entanglement + *multi-verse and tunneling*) to perform operations on data.

10. Quantum superposition – is a fundamental principle of QM that holds physical system (electron) in all particular theoretically possible states, UNTILL it is observed or measured (so it gives only one corresponding result)

11. QUANTUM STATE – SIMPLY A STATE Quantum entanglement is a physical phenomenon that occurs when pairs of groups of particles ( 2 electrons) are interacting -> the quantum state of each particle cannot be described separately, but the quantum state can be given to the WHOLE SYSTEM.

12. So classical computer uses bits, but quantum computer uses QUBITS If classical computers use current, quantum physics uses particles for data operations,

14. ELECTRON IN THE PHOSPHORUS All electrons have magnetic field -> they have a spin and we have to differentiate it. By placing them in a strong magnetic field, they will align in that field by result having the lowest energy state (zero state-spin down – 0) ON OUR WAY OF GETTING QUBITS

15. The problem is at the room temperature this electron would start BOUNCING because of instability. Alan Durnev

16. THE SOLUTION IS… TO COOL DOWN THE WHOLE SYSTEM TO THE TEMPERATURE OF THE OUTER SPACE (~ - 235 C)

17. In order to save some information on qubit we have to spin it UP by heating it with a pulse of microwave of a very specific frequency (~45,021 GHz), and to get the superposition we have to stop heating it at some random moment, so that electron would stay at this position. Bra-ket notation

18. THE PROBABILITY BEFORE MEASURING

19. THERE IS NO POINT TO WORK WITH 1 ELECTRON, AS POWER COMES WITH 2 One classical bit can be in one of two conditions or, but the qubit Where |a|^2 and |b|^2 are probabilities get those positions and is a superposition vector

20. FAST EXAMPLE We have 00,01,10,11 – those are still 2 bit information, as (2 qubits) =, where (8 dimensional ket vector for sphere). So that 1 qubit contains 4 bits of information (a,b,c,d), when 2 bit have only 2 bits of information…

21. SO… The amount of classical information contained in N qubits = 2^N bits, whereas N bits have N of bits (classical information)! But it would give an answer with a certain probability! The power of exponentials lets us to imagine 2^300: which means that we need 2^300 classical bits to describe all 300 positions of qubits and this is nearly as amount of particles (atoms) in the UNIVERSE!

22. Quantum Computers unmeasured OUTPUT has ALL POSSIBLE results and only 1 will be chosen. Alan Durnev

23. All possible combinations simultaneously

24. “Achieving perfection is hard, but remaining perfect… That’s impossible!” – quote If we want to measure any of information that is being calculated at the time of quantum calculation or just see how it happens it will vanish…Our interest would ruin the superposition (Schrödinger's cat paradox). It is named as quantum decoherence.

25. QUANTUM COMPUTERS NOWADAYS The timeline of quantum computer takes its beginning in 2001 when a 7-qubit processor was used. After that many interesting researches were done, but: 1.In 2011 D-Wave Systems announced the first commercial quantum computer, with 128 qubits 2.In may 2013 Google announced it was launching Quantum Artificial Intelligence Lab, hosted by NASA’s Ames Research Centre and a 521 qubit D-Wave quantum computer 3.Documents were provided by Edward Snowden that U.S. NSA (National Security Agency) is running a $79.7 million research program (named, “Penetrating Hard Targets”)

26. D-WAVE SYSTEMS

27. LOCATED IN NASA

28. Josephson effect

29. PROGRAMMING FOR IT A few programming languages that allow using quantum algorithms on a high-level construct for solving real world problems. Quipper (based on Haskell): For example, the following code implements preparation of a superposition

30. WHAT IS POSSIBLE WITH QC AND WHAT IS NOT It will not make a YOUTUBE HD video load faster, as well as will not make saving word document faster, as they are powerful for only strict types of calculations available for computer parallelism. So it is not a replacement for a normal computer. With a stable P class (type of algorithms) problems it may be even slower, depending on input data. But only the number of data that is needed for calculation starts growing, the quantum computer gains its efficiency. 10^x, x = 1000000000000000000000000000000000000 Quantum Computer may give the answer within a polynomial time.

31. Quantum Computer would give an ability to decrypt many of the cryptographic systems within a polynomial time. For solving hardest algorithms (NP class) or even make progress in researching AI. ALAN DURNEV

32. Thank You.