Quantum Computers and the Tech-World Part1-Introduction
In this fast-paced world, is our computer fast? No, I’m not talking about the PCs that you own, but among all the existing ones you may know about, maybe something like a supercomputer. Sorry, buddy! Even supercomputers fail to solve some complex calculations if provided with an enormous amount of data. For this, we need something out-worldly.
What if I said that such a system already exits on earth? Moreover, some organizations such as IBM, NASA, and Intel are currently using them and performing more research to provide this to the common masses. That’s great news, right? Well, I’m talking about quantum computers.
Intel plans to invest about $50 million over the next ten years into research on quantum computing, together with QuTech, while IBM builds on more than three decades of research effort in this field and offers a cloud service to let students and researchers get practical ‘Quantum Experience’. The European Commission launched a euro 1 billion flagship initiative on quantum computing in 2018 with substantial funding for the next 20 years. That’s a mighty investment and shows how supreme this concept will become in the coming years.
Surprisingly the idea on which these computers work is out-of-the-world concept, the ‘Quantum Theory’ about which you might have studied in your Physics classes. Don’t remember those? Calm down I’ll write them down for you!
Go ahead and explore the concept. Who knows, maybe you’ll become one of those engineers working with such a computer soon! Happy reading! :D
What is new about Quantum computers?
Quantum computers are not an improvised version of classical computers(The ones which we use until now). Quantum computers are altogether a new system/concept, but since they calculate and perform functions like computers hence called quantum computers. They are indeed very different from classical computers because the basic principle on which they work are poles apart. If a traditional computer is a cycle, then a Quantum computer is a sports car. Numerous bicycles you join, it won’t be anything similar to a car in terms of speed. Yes, a quantum computer is a supremely powerful tool!
To understand quantum computers, let’s dig into the basic working of classical computers.
Bits are the basic building blocks of classical computers. We encode information as a sequence of bits. For instance, the letter ‘A’ has an ASCII value of 65 (decimal representation), which converted to the 8-bit series is 01000001 (binary representation).
Every bit can have a value of either 0 or 1. Using a transistor as a data processor, which like a switch, can let the current/information pass through them(1) or block them(0). Hence we can represent complex information as a combination of bits. Several transistors (having the size of a few atoms approximately 14nm) combine to form logical gates (e.g., AND gate, NOR gate), which in turn connect to create meaningful modules embedded in a computer chip to process data like adding numbers. If we can add, we can multiply, and if we know multiplication, we can do anything! Pretty cool!
How do Quantum computers work then?
The basic building blocks are qubits (quantum bits). Here, the sizes we deal with are tiny because we perform calculations with the help of electrons. If an atom is a football ground, then a fingernail is a nucleus and a speck of dirt, it is an electron! I hope now you got how small an electron is. Phew! That’s too small even to imagine then think about how tough it is to work with them. That is how technology advances. Right? Small is indeed big!
In quantum reality, Physics works differently from the predictable one, because here the particles possess wave nature. A qubit also has two quantum levels (due to electron’s spin/ magnetic field) of 0 or 1 like a bit. But it possesses both 0 and 1 state simultaneously and in any proportion through superposition (Mixing of two waves). But once a qubit is measured/observed, it has either of the two particular states. This is just like the concept of Schrodinger’s Cat.
A cat is both dead and alive, if we keep it inside a box having poison. Until we open the box, we do not know in what state the cat is. Hence it is in a superposition of being both dead and alive. But once we open the box, it is either dead or alive. That’s interesting! These concepts can’t be applied in traditional computers since this doesn’t make any sense to them just like us! :P
Hence scientists have developed new quantum computers that understand quantum theory.
How is quantum better than classical computers?
Get some coffee so that you don’t sleep☕. Let us take an example of a 3-bit classical system. It can have ²³ possibilities, which means 8, it can use only one out of these at a time, and since the classical computer performs the task one by one, it has to work eight times, which is time-taking. Whereas 3-qubits in superposition can hold all possible configurations of input data simultaneously. For every qubit added, this number becomes too large(2^n if n qubits are present) and hence can compute the massive amount of data in parallel! We term this as quantum parallelism.
Qubits have another property of entanglement. It means a qubit can react with each other however far they may be, which is advantageous, as by looking at an entangled qubit, we can deduce the properties of other qubits.
A logical gate provides a specific output for provided input while a quantum gate manipulates the data, rotates probability, and produces another superposition as an output. Quantum computers manage probabilities, collapse superposition, and provides a sequence of 0’s and 1’s. So all the calculations are done simultaneously in a fraction of seconds, unlike classical ones who calculate one by one.
Quantum gates are reversible due to the unitary property of the transformation matrices. It means we can reverse any quantum circuit by applying the sequence of inverse quantum gates in reverse order to the output state vector. Reversible have the possibility of ‘undoing’ algorithms. Seems pretty amazing! We can reduce the energy consumption of computers. Since each input channel would be associated with its unique output channel, no bit would be erased, and hence, no energy would be dissipated during computation. Only the initialization of registers and the storage of the computed answer would require some energy. However, reversible computing is not yet practical.
That was too technical but brief hence difficult to understand so chill!
Treat yourself with a bar of chocolate🍫 if you’re reading this. :)
Let me jot down the key points so that you know what to remember.
- Quantum computers follow parallelism, which means like a superhuman, it can do multiple tasks/calculations simultaneously. (Who said multitasking is terrible?)
- They follow the principle of entanglement. Ain’t that super cool that you can know any qubits data by looking at another qubit?
- Reversibility is epic. Imagine you can say what was the input by having the output only.
All seems too good about this! Well, everything can’t be perfect, so lets read about the things that need to be fixed by quantum computers.
Individual classical computations yield the exact output to all possible combinations of input data. In contrast, the outcome of the measuring procedure at the end of a single run of a quantum algorithm is a ‘randomized’ selection from the set of all possible solutions. Quantum algorithms, therefore, require special techniques to provide the desired solution and not just a random choice, which is a challenge to calculate.
Many well established classical concepts will require a complete redesign if they make use of ideas that violate one or more quantum theorems. Furthermore, quantum computers need extra effort to detect and correct errors since all qubit technologies available today are very fragile and prone to errors since the qubits remain in a coherent state for just a fraction of a second. Because of the fragility of entanglement, it has so far been possible only to create quantum computers with a handful of qubits.
Another issue with these computers is that since the calculations are based on an electron’s spin, an increase in temperature will change the way an electron behaves; hence will give false output.
For this, we need a huge cooling system that sets the temperature to extreme low (near absolute zero), which are expensive as well as occupy large volumes of space.
I hope now you understood why the picture you saw of the quantum computer before seemed so big while I’ve been emphasizing the smallness of qubits. XD
Well, whoever said, ‘don’t judge a book by its cover’ is wrong. Don’t kill me for saying this. Quantum computers work on a complex concept as complex they look. In case you’re not understanding these concepts let me tell you that’s normal and if you’re then…. :D
That was long even to read, and remembering them is a hard job. Don’t worry, I’ve summarized them for you!
- Quantum computers provide output from ‘randomized’ selection from the set of all possible solutions, so they need precise input and perfectly calculated assumptions.
- Ultimately new computers have to be built from scratch since quantum computers can’t keep a copy of data, and we can’t apply complex quantum algorithms to classical ones.
- As I stated before, they are very complex(prone to errors due to electron instability)Their construction and maintenance are strenuous, expensive, need special infrastructure and expert knowledge
Though it may seem a difficult task to accomplish these challenges, the usage of quantum computers in the future will be tremendous. We will use these concepts in applications ranging from space technology, healthcare, prediction of floods, to securing communication. So investing time, money, brain, and energy is indeed worth-wile. Though this technology is in its initial stages, but is being developed at a great rate! Thanks to researches, engineers, and scientists. I’m positive that we’ll be soon using a quantum computer in our homes!
Conclusion
We read the basic principle on which a classical computer differs from a quantum counterpart. We know the important features of quantum technology and how they need to be improved further so that they can be applied to a larger area of the globe. I hope reading this has ignited your curiosity to see their real-world application and its impact on our current technology.
Thank you for reading and for having patience! Treat yourself and me by clicking on 👏 as this will motivate me to write more such articles so that you can enjoy reading more!😁Merry Christmas!🎄
About the Author
Sneha Shukla is a sophomore, pursuing BTech in Electronics and Telecommunication from IIIT Bhubaneswar. She is currently working as an intern at Techbootcamps as a technical content writer. She is passionate about Blockchain, space technology, and IoT and works on front end web development too! Her hobbies include reading, writing technical blogs, and promoting new and promising technologies.
References
Image source — Google images
