Day9 of #Quantum30 Challenge

Saiyam Sakhuja
8 min readAug 9, 2023

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Hello fellow learners! I am excited to share that I started a new phase of learning in the realm of Quantum Computation. Enough with the underlying concepts of Quantum physics; today I started to learn what a Quantum Computer is. With the end of Day 9 task of #Quantum30 Challenge from QuantumComputingIndia, I have enough idea of what quantum computer is, what they can be capable of, etc.

The first resource is “Quantum Computers Explained — Limits of Human Technology” by YouTube channel Kurzgesagt. Let’s go!

Quantum Computers: Beyond Human Technological Boundaries

Human technology, from its primitive origins of fire and tools, has evolved into sophisticated machinery. The pinnacle of this evolution has been the enhancement of our cognitive abilities through computers. Over the decades, computer power has grown exponentially, enabling shrinking sizes and increasing power. However, we are approaching physical limits, with components nearing the size of atoms. To comprehend this challenge, we need to grasp some fundamental concepts.

Basic Building Blocks of Computers

A computer comprises basic components responsible for data representation, processing, and control. Computer chips consist of modules containing logic gates, which are made up of transistors. Transistors serve as data processors, acting as switches that allow or block the flow of information, represented in bits (0s and 1s). Logic gates, like the AND Gate, perform simple operations, while combinations of gates form modules for more complex tasks.

Quantum Physics and Shrinking Limits

Traditional computers operate based on classical physics. However, quantum physics emerges when dealing with particles at atomic scales. Transistors, now nearing atomic sizes, face quantum tunneling, where electrons move through blocked pathways. In the quantum realm, conventional computers become inadequate due to unpredictable behaviors.

Quantum Computers: A Paradigm Shift

Quantum computers exploit quantum properties to overcome shrinking limits. They use qubits, the quantum counterparts of bits, which can exist in various states simultaneously due to superposition. However, upon measurement, a qubit’s state collapses to one of the possible outcomes. Superposition enables parallel processing, with multiple qubits processing numerous configurations at once. Entanglement, another property, allows entangled qubits to instantaneously influence each other’s states, irrespective of distance.

Harnessing Quantum Power

Quantum computers manipulate qubits using quantum gates, rotating probabilities, and superpositions. This enables them to perform vast calculations simultaneously. While they won’t replace regular computers, quantum computers excel in certain areas. Database searches are notably efficient, requiring only the square root of the time needed by classical computers. Quantum computers also pose a threat to IT security, potentially breaking encryption systems quickly. They hold promise in simulating complex quantum systems, revolutionizing fields like medicine.

A Future of Uncertainty and Exploration

The potential of quantum computers is uncertain. They might remain specialized tools or trigger a revolution. Humanity is on the brink of technological exploration, pushing the boundaries to understand the extent of our capabilities. As quantum computers redefine the limits of human technology, we embark on an uncharted journey toward a new era of computation.

The second resource for Day 9 is “The Insane Mechanism of a Quantum Computer?” from the YouTube channel Arvin Ash. Let’s learn!

Unveiling Quantum Computers: A Revolution in Computing

In our modern lives, computers have become an integral part of daily activities, from work to leisure. Amid this technological landscape, a groundbreaking innovation has been quietly advancing: quantum computers. These machines, under development for decades, possess the potential to redefine fields like medicine, communication, encryption, and artificial intelligence. Giants like Google, IBM, and Microsoft are channeling substantial investments into this cutting-edge technology. Let’s delve into the essence of quantum computers, explore their distinctions from conventional computers, and decipher their inner workings.

Shared Components of Computers

Computers, whether quantum or classical, share fundamental components. Power supply energizes their operations, while data storage is facilitated by devices like hard drives and SSDs. Yet, data transfer speed between storage and processing remains a challenge. To address this, computers employ RAM — Random Access Memory — which is faster and closer to the processor. However, it’s costlier and volatile, leading to data loss during power disruption. The central processing unit (CPU) is the brain, managing computations with data from RAM. Motherboards interconnect these components, forming a functional whole.

Transistors vs. Qubits: The Heart of Quantum Computing

A classical CPU operates with transistors, akin to binary switches representing 1s and 0s. In contrast, a quantum computer’s key feature is the qubit. A qubit is a superposition of both 1 and 0, exploiting quantum objects’ ability to exist in multiple states simultaneously. This superposition property opens a realm of possibilities, enabling parallel computations. Qubits can be realized using diverse quantum objects, such as photons or electrons.

Harnessing Superposition and Quantum Algorithms

Superposition grants quantum computers an exceptional capability — simultaneous processing of multiple questions. Quantum algorithms, cleverly devised by programming experts, maximize the probability of obtaining accurate results. By leveraging destructive and constructive interference, these algorithms guide superpositions toward correct outcomes, transforming qubits’ potential into meaningful classical results.

Quantum Computers’ Unique Problem-Solving Power

Quantum computers excel at specific problems, not by accelerating typical computations, but by executing multiple functions for various inputs simultaneously. For instance, they can solve complex search problems with unparalleled efficiency. This advantage stems from the quantum search algorithm, which drastically reduces the operations required to find specific data points in large datasets.

Building Quantum Computers: Challenges and Cooling

Developing quantum computers poses challenges. Maintaining qubits’ superposition mandates isolation from the external world. To preserve this delicate state, extreme cooling near absolute zero is essential, as heat fluctuations can disrupt the superposition. Furthermore, qubits within the computer must interact swiftly, necessitating intricate interconnections.

The Universe as a Quantum Computer

The concept of the universe as a giant computer is thought-provoking. Just as computers process data, the universe processes the present to compute the future based on the laws of physics. These laws effectively act as the universe’s algorithm, determining the course of events.

As quantum computers emerge from labs and edge closer to practicality, they bring the promise of a technological paradigm shift. Their unique capabilities offer a glimpse into the untapped potential of computing, holding the potential to reshape our understanding of computation and the universe itself.

The third video resource is “How Does a Quantum Computer Work?” from the amazing YouTube channel Veritasium. The speaker went to UNSW in Sydney, Australia, to meet Prof. Andrea Morello. The professor explained how quantum computers give exponential speedups and why quantum computers will not replace classical computers. Let’s learn!

In classical computing, operations are conducted using binary bits that represent either zero or one. Quantum computers, on the other hand, utilize qubits, which possess a unique property: they can be in a superposition of both zero and one states simultaneously. This property underpins the exceptional computing power of quantum machines.

Various physical entities can serve as qubits, such as single photons, nuclei, or electrons. Researchers are exploring the use of the outermost electron in phosphorous as a qubit. The principle behind this lies in the electron’s magnetic property, known as spin. Similar to a compass needle aligning with Earth’s magnetic field, electrons align with an applied magnetic field. The lowest energy state corresponds to spin down (zero state), while spin up (one state) requires energy input.

Intriguingly, quantum objects like electrons can exist in superposition, where coefficients indicate the probabilities of different states before measurement. Two interacting qubits offer four potential states, akin to classical two-bit systems. However, quantum mechanics allows superpositions of these states, expanding the quantum system’s information capacity.

A significant distinction emerges in the amount of information encoded. N qubits can encode 2^N (2 to the power of N) classical bits. For instance, 300 qubits yield 2³⁰⁰ classical bits, exceeding the number of particles in the universe. Despite this power, quantum measurement collapses superpositions into a single state, emphasizing the importance of designing quantum logical operations for effective measurement.

However, quantum computers are not universal replacements for classical ones. Their advantage lies in specific algorithms that leverage superposition to perform parallel computations. Quantum computers aren’t uniformly faster; rather, they excel at reducing the total number of operations needed for certain calculations. Quantum computing’s potential lies in harnessing superposition and entanglement for specialized problems, not in everyday tasks like browsing or word processing.

The fourth resource for Day 9 is “Quantum Computers, explained with MKBHD” from the YouTube channel Cleo Abram. This resource was more of a quest for the speakers, Cleo Abram and Marques Brownlee.

Introduction to Quantum Computing

The video begins with a sense of awe and anticipation as the hosts, including tech YouTuber Marques Brownlee, explore the concept of quantum computing. They acknowledge the confusion and misinformation surrounding this advanced technology, highlighting the need for a clear explanation. Quantum computers are depicted as game-changers that defy conventional computing norms. The hosts express their intent to demystify quantum computing and its potential impact on our lives.

The Quantum Difference and Quantum Supremacy

The hosts emphasize that quantum computers are distinct from classical computers and should not be perceived as mere upgrades. Quantum computers are introduced as fundamentally different, using qubits that exist in superpositions of zero and one states. This unique property enables them to perform specific tasks with exponential efficiency. The concept of “quantum supremacy” is mentioned, suggesting that the nation achieving a functional quantum computer gains a significant advantage.

Source: https://youtu.be/e3fz3dqhN44

Challenges in Understanding Quantum Computers

The hosts admit the challenge of comprehending quantum computers, pointing out that even experts have varying levels of understanding. They draw an analogy between classical and quantum computing using waves and probabilities to illustrate the contrasting principles. Quantum computers are noted for their ability to process complex data structures, potentially revolutionizing various fields.

Exploring Quantum Computers at IBM

The hosts visit an IBM laboratory to witness a quantum computer. The immense cooling technology required to maintain the computer at temperatures colder than outer space is showcased. The physical setup of the quantum computer is revealed, providing a tangible sense of its complexity. The hosts express their excitement at being able to see and touch a real quantum computer.

Source: https://youtu.be/e3fz3dqhN44

Working of Quantum Computers and Applications

The working principle of quantum computers is explored further. Quantum bits (qubits) are described as complex entities with probabilities of being in zero or one states. The interaction of probabilities among multiple qubits during computation is compared to the behavior of waves in a pond. Quantum computers are positioned as proficient in solving complex problems and simulating natural phenomena, particularly at the molecular level.

Quantum Computers and Encryption

The hosts delve into the quantum computers’ potential to break encryption, focusing on an algorithm named after Peter Shor. Shor’s algorithm can potentially compromise encryption systems, making secure transactions vulnerable. The importance of quantum-safe encryption algorithms to counter this threat is discussed, with the prediction that a transition to quantum-safe encryption will occur within a few years.

Future of Quantum Computing

The video concludes with an optimistic outlook on the future of quantum computing. The hosts highlight the rapid advancements in quantum technology and the potential for discovering new applications. The analogy of quantum computers as “submarines” is introduced, suggesting that humanity is only beginning to explore the vast potential of quantum computing. The hosts emphasize that the evolution of quantum computing is limitless and holds promise for both technological advancements and a deeper understanding of the quantum world.

Google’s Sycamore quantum computer. Source: Rocco Ceselin/Google

Thanking QuantumComputingIndia #Quantum30

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