Gadgetory

quantum physics is no simple subject to explain or attempt to even comprehend quantum computers are no different nevertheless this is your by popular demand here is how a quantum computer works trusty whiteboard here and I want order to explain quantum computers how they work on a basic level or as basic as I can possibly make it we have to understand how the classical computing system works based on a binary code using just ones and zeros now imagine a transistor like a switch I kind of ran through this in this video here but I'll go over it again just for those who haven't watched that video yet so transistors are essentially switches this is the open state we'll denote that as zero and this is the closed state well denote that as one in this state here current is allowed to flow and in the state here current can not so binary transistors open and close to indicate 1 and 0 and threshold voltage does not reach a gap in the current is created indicating a zero for false whether it's a one or zero really depends on the algorithm being used they'll always be opposite so for our examples in this video one will equal true which equals a closed circuit and zero equals false which equals an open circuit this is how all data and modern computing systems is transmitted and processed and you can imagine how multiple switches multiple transistors billions of them actually in a single processor opening and closing billions of times a second can equate to some serious computational power but quantum computers make pcs like this one behind me seem like basic calculators they aren't binary systems per se although we often use 1 and 0 to denote the range of values quantum bits or qubits can denote the word quantum and phrases like quantum mechanics and quantum physics which inherently makes them sound very daunting literally just describes the energy states of very small particles and the reason why we've only started using this word in the past when I'll half a century or so it's because we never had tools small enough and precise enough to measure the energy states of things like electrons photons and even just whole atoms but thanks to research done by folks like vona heisenberg serge haroche and david Weinland we now know that it also describes how an electron can be in two places at once this is from where quantum computing is derived instead of ones and zeros regular bits qubits can represent an infant range of values between one and zero think of them like probabilities and unlike the classical counterpart qubits can be physical objects like electrons and photons imagine a compass with one pole denoted one and the other pole denoted zero the needle of a compass can swing whenever it wants wherever it wants within the system but it can never point to anything higher than one or lower than zero instead it can point to areas in between the two poles and represent the likelihood of either becoming a 1 or 0 once the qubit is processed and observed this area in between is what's known as superposition when we read and interpret classical let's say 3 bit binary data streams we understand that 8 outcomes are possible since there are only two possible States and 3 bits to raise to n where n is 3 equals 8 so eight possible outcomes here and all probabilities of which must equal one so there's a 100 percent chance that a 3 bit binary system will yield one of these values since they're the only values possible with three digits and two numbers a quantum three bit system works a bit different however since each qubit can denote any complex number between 0 and 1 then the sum of the squares of each complex probability must equal 1 for a 100% probability when we make a measurement of a 3 bit quantum system the values of the particles in each orientation collapsed to a classical state of binary by the computational power of a 3 bit quantum computer far exceeds that of classical systems where binary systems require to raise to the power n bits quantum computers can express the same amount of information in just in qubits for scale with just a 30 qubit quantum computer would be capable of nearly 10 teraflops of floating operations per second a process which in today's modern technology would require billions of transistors that's pretty awesome but don't get too excited because the modern applications of quantum computers are still yet to be seen in a sense we use them a lot for like predictions and probabilities because you can do multiple operations super fast parallelism and quantum computers is insane but to watch a Netflix er watch YouTube or even I don't know render a video quantum computers aren't all that viable yet simply put modern processors already do a pretty darn good job at those simple tasks on PCs so it wouldn't make much sense to replace them which can be we're from like 50 bucks to maybe 500 bucks with super expensive multi-million dollar quantum pcs they don't belong in your living room they belong into research laboratories QCs also get extremely hot and have to be cryogenically cooled down to roughly zero Kelvin in most cases they must also be shielded from the outside world since even the smallest magnetic disturbances can offset a qubits reading and promote 2d coherence that's the word you don't want to hear if you're in the QC business they're also extremely large expensive and difficult to maintain the viability of quantum computers might change as our infrastructure and technology does but I still expect we'll be using binary systems for quite some time they just work we don't have to worry about things like quantum decoherence insane shielding or overheating No okay maybe a little overheating but not on the same scale but much like early binary computers quantum computers today are very large who knows in say the next 50 years we may shrink quantum processors or what might become quantum processors down to the size of a modern transistor processor there are about two billion transistors in the space a space really no larger than the surface area of my thumbnail but imagine 2 billion cubits in the same space that is insane computational power that's a lion's mane I am worried though by about that time I expect we'll have discovered a true artificial intelligence which will mean the end of ourselves basically terminators roaming everywhere if you liked this video be sure to give it a thumbs up thumbs down for the opposite click that red subscribe button if you haven't already and click that doll notification icon by the way so you get notified more videos like these go live this is science studio thanks for learning with us