Beginner's Guide to Quantum | Quantum 101

Since classical computing emerged in the mid-twentieth century, there has been exponential progress in computer design, with processing power roughly doubling every few years (called Moore's law) But even if Moore's law keeps holding, there are many classes of problems that strain the ability of classical computers. Problems classical computers can't solve efficiently, and some may never be solvable with classical computing, no matter how large supercomputers get. For example, properties of atoms and molecules can be found by solving the Schrödinger equation. However, the problem gets harder the more components, the more atoms you add, so exact calculations are hard above just a few atoms, and approximate solutions are hard above a few dozen atoms. Instead we build a new system of computing, using quantum bits, or qubits, called quantum computing. 0:00 About me! 1:05 Why Quantum? 1:41 Qubits 2:45 Quantum Properties 5:11 Quantum Gates 6:05 Quantum Algorithms 9:35 What's Next? 11:15 Will Quantum Replace Classical? Join this channel to get access to perks like behind the scenes and support my channel! https://www.youtube.com/channel/UCzaYH6WeohiHKj3Ih_GdZdQ/join or the same perks over on Patreon: https://www.patreon.com/amarchenkova In this traditional binary approach to computing, information is stored in bits that are represented logically by either a 0 (off) or a 1 (on), like 0 or 5 Volts. Quantum computing uses information in a fundamentally different way than classical computing. Quantum computers are based on quantum bits (qubits), a fundamental unit that can exist in both states 0 and 1 simultaneously (superposition).which exist in a probability, or superposition, of zero and one - and until you measure of observe it, you don't know which state it will collapse into. But that doesn't mean we can just put a regular bit into 2.5V and call it a day. A quantum computer is a system that uses quantum properties, like superposition and entanglement, to perform computations. So not only does the qubit have to be quantum mechanical in nature, but we also utilize these quantum mechanical properties to perform calculations. Entanglement is another fundamental quantum property we need to harness to do quantum computation. Schrodinger called this THE defining characteristic of quantum mechanics, and as early as 1935 in the famous Einstein-Podolsky-Rosen EPR paper, we have shown the effects of quantum entanglement. When we say particles are entangled, it means that quantum states are linked to each other - the state of one cannot be described without another (they are not "separable"). This is a purely quantum phenomena and doesn't exist in the classical world. Information is almost like it's spread across the particles. So how do we control quantum computers to actually simulate quantum states, do optimization problems, and solve hard math problems like factorization? Universal gate quantum computers have a broad application. This system relies on building really reliable qubits where basic quantum circuit operations, or gates, can be put together to create any sequence, running more and more complex algorithms. Quantum computers, however, have their own set of gates that are very different from the set of classical computing gates. A big misconception is that quantum computers work by trying every possibility at once. But Quantum computers don't speed up every problem. They are faster for a certain set of problems. There are only a few dozen or so quantum algorithms. Now, in traditional computer science terminology, "algorithm" means a set of instructions. But when we talk about quantum algorithms, we mean instructions that actually harness these quantum properties of superposition and entanglement, and can potentially solve these mathematical problems faster than a classical machine. But wait, only a few dozen quantum algorithms that are useful? Like I mentioned before, eEven though there's a limited number of quantum algorithms, the ones that do exist can have a huge impact on very important problems. #quantumphysics #quantum101 #introtoquantum