In the ever-changing technological realm, quantum computing is one of the most promising and revolutionary industries. By using the principles of quantum mechanics, they have potential for solving complex tasks with an unfathomable speed, which greatly exceeds the capacities of traditional computers.
Features of quantum computing, it’s fields of use and Achilles Heels — read more about it below.
What is quantum computing?
Quantum computing is the new type of computing using principles of fundamental physics for exceptionally rapid performance of highly complex tasks.
In the beginning was the quantum mechanics
The story of quantum mechanics was born from a Latin word quant meaning ‘quantity’ or ‘as much’. It is the smallest discrete particle of an entity. For instance, a quant of light is a photon, and a quant of electricity is an electron.
Modern use of the quantum concept in physics was proposed by Max Planck in 1901. He set out to explain blackbody radiation and how objects change color upon heating. Planck suggested that energy is emitted not as a continuous wave, but in discrete packets, or bundles, which he called energy quanta. This assumption led to the discovery of Planck’s constant, a fundamental universal quantity.
The discovery of quanta and the quantum nature of subatomic particles sparked a revolution in physics. A separate branch, known as quantum theory or quantum mechanics, emerged. Subatomic particles behave counterintuitively; for instance, a single quantum of light, or photon, can pass through two slits in a material simultaneously. Schrödinger’s cat is a well-known thought experiment describing a quantum particle in a superposition—a state in which its wave probability form has not yet collapsed. Particles can also become quantum entangled, causing them to interact instantly over distances.
Quant in computing
Quantum computing takes advantage of the nature of subatomic particles to perform computations, unlike classical computing, which relies on electrical signals. A quantum computer uses qubits instead of binary bits. By programming the initial state of a qubit, the issue of superposition collapsing can be resolved.
Research in quantum computing focuses on linking more qubits together to solve increasingly challenging problems.
Quantum computers can perform certain calculations much faster than classical ones. Traditional computers must test every option one after another to find an answer. For certain tasks, exploring all possible options can take plenty of time. Quantum computers, however, don’t need to try each option — they can find an answer almost instantly.
Once quantum computers demonstrate the ability to solve tasks like prime exponentiation and the traveling salesman problem faster than classical computers, quantum supremacy will be achieved.
Exponentiation is a critical function for modern cryptographic systems. Experts currently anticipate that quantum computers will render existing cryptographic systems insecure and obsolete. There are still ongoing efforts to develop post-quantum cryptography to create algorithms resistant to quantum attacks, while still able to be used by classical computers.
Specifics of quantum computing
Superposition
In quantum mechanics, particles can co-exist in various states all at once. This principle is represented through qubits (quantum bits), which can be simultaneously 0 and 1, contrary to classic bits that can be either 0 or 1. It allows quantum computers to process vast data volumes in parallel, exponentially expanding their computing power.
Entanglement
A phenomenon in which the state of one particle becomes dependent on the state of another, even if great distances separate them. In quantum computing, entangled qubits can be used to perform coordinated operations, enabling more efficient computation and communication.
Wave-particle duality
According to quantum mechanics, particles exhibit both wave-like and corpuscular properties. This concept plays a crucial role in the development of quantum algorithms, which utilize the wave-like nature of qubits to perform complex calculations.
Quantum parallelism
Thanks to the principles of superposition and entanglement, quantum computers can process an enormous number of calculations simultaneously. This feature allows quantum computers to solve certain problems faster than classical ones. For example, the factorization of large numbers, a complex task for classical computers, can be performed much faster using quantum algorithms like Shor’s algorithm.
Quantum supremacy
This term is used when a quantum computer can solve a problem that the traditional computers can’t, or when it performs it a great deal faster. In 2019, Google’s Sycamore quantum computer achieved quantum supremacy by completing a computation in 200 seconds — a proof that numbers produced by a randomizer are truly random. A supercomputer would have taken 10,000 years to do the same. However, advancements in supercomputing continue. In 2023, Google developed another quantum computer that completed the computation in 6.7 seconds, while the world’s most powerful supercomputer, Frontier, would need 47 years.
Decoherence, or quantum’s Achilles Heel
While the principles of quantum mechanics provide quantum computers with power, they also pose one of its biggest challenges: quantum decoherence. This phenomenon affects the delicate state of qubits, causing them to lose their properties due to interactions with the environment. Maintaining qubit coherence for a sufficient period (known as “coherence time”) to complete computations remains one of the most significant obstacles in quantum computing.
Quantum teleportation
It is reached thanks to the principles of entanglement and quantum measurements. But what is meant is not a teleportation as we imagine in, but rather an instant transmission of quantum information. The researchers have successfully completed an experiment with quantum teleportation on a distance of several kilometers.
Reversibility
In classic computing, many operations are irreversible. For example, if you delete a file, it will basically disappear. However, in quantum computing, operations are reversible thanks to the unitary nature of quantum evolution. It means that for each step, there is a step back which can cancel out the previous one. That’s what allows for quantum errors’ correction that is a crucial aspect for reliable quantum computing.
There are no copies in the quantum world
A theorem on impossibility of cloning ― the fundamental principle of quantum mechanics, which holds that no identical copy of any given unknown quantum condition can be created. This principle has deep outcomes for quantum computing and quantum information theory. It is one pf the key factors making quantum communication safe, as any effort to copy quantum information will lead to its destruction.
Uncertainty principle
Heisenberg’s Uncertainty Principle is a fundamental concept in quantum mechanics, stating that it is impossible to simultaneously measure the exact position and momentum of a quantum particle. In quantum computing, the uncertainty principle implies that there is always a degree of uncertainty when working with quantum states. This can make quantum systems challenging to control and manage.
Applications of quantum computing
- Cryptography and security. Shor’s quantum algorithm can rapidly factor large numbers, potentially breaking widely used cryptographic schemes like RSA and ECC. To conquer this, there are post-quantum cryptography researches, developing quantum-resistant algorithms to protect sensitive data from quantum attacks.
- Drug discovery. The medical industry could use quantum computing for developing new drugs and genetically oriented healthcare. Quantum computing may also enhance advanced DNA research.
- Optimization in finance and logistics. Quantum computing can efficiently analyze massive financial datasets and optimize investment strategies to achieve higher profit rates with lower risks.
- Artificial intelligence and machine learning. When quantum computing is combined with machine learning, it could lead to breakthroughs in AI. Quantum algorithms for pattern recognition, data analysis, and optimization could significantly enhance AI models’ capabilities.
Limitations of Quantum Computing
Quantum computing offers a far-reaching prospect for developments and problem-solving in many industries. However, they still have limitations.
Stability and qubit decoding
Qubits are highly sensitive to external influences, which leads to decoherence — qubits lose their quantum state and shift back to classical bits.
Error correction and fault tolerance
Quantum computers are prone to errors due to qubit decoherence. Implementing error correction and fault-tolerant quantum circuits is crucial to achieving reliable quantum computations.
Hardware limitations and scalability
Building practical, large-scale quantum computers remains a significant challenge. Current hardware designs have limitations in the number of qubits, connectivity, and error rates. Advancements in quantum hardware are essential for creating powerful and scalable quantum systems.
Competition
Quantum computing is highly competitive, with major tech companies and research institutions competing to reach breakthroughs in this industry. Collaboration and open research initiatives are essential for the effective development of quantum technologies.
The future of quantum computing
It will be both exciting and uncertain. Although quantum computing has made significant progress, practical quantum computers that outperform traditional ones in general-purpose tasks are still not designed. However, ongoing research, development, and increasing investments in this field are rapidly pushing the boundaries of quantum technology.
Over the next five to ten years, we may witness significant advancements in quantum hardware, error correction methods, and new quantum algorithms. As these achievements unfold, quantum computing may become more accessible to researchers, industries, and eventually, society at large.
The widespread adoption of quantum computing holds profound implications, reshaping industries, encryption methods, and scientific research. Addressing ethical and security issues will be critical to ensuring responsible and beneficial development of quantum computing.
