Quantum computing is a field of computing that uses quantum mechanical phenomena. Such as superposition and entanglement, to perform computations. Unlike classical computers, which use bits, it uses quantum bits, or qubits, that can exist in a superposition of both 0 and 1 states simultaneously.
Quantum computers have the potential to break current encryption standards by quickly finding the prime factors of a large integer, which would take classical computers thousands of years to do. Although real quantum hardware exists today, it is not yet powerful enough to achieve this feat.
Quantum vs Classical Computing
However, technology is advancing rapidly. The researchers predict that we will soon enter an era of quantum advancements, where quantum computers will accelerate classical computing. This allows computers to perform certain types of calculations. For example, Shor’s algorithm, a quantum algorithm, can factor large numbers exponentially faster than any known classical algorithm. This has significant implications for cryptography and could potentially render many current encryption methods obsolete.
But there are still many technical obstacles that must be resolved for quantum computing. This includes the problem of decoherence, which causes errors in quantum computations. Still, researchers are actively working on developing quantum hardware and software. Classical computers use bits, which are switches that can represent either a 0 or a 1. Although most modern computers still use this strategy, and how well it has served us, it is unable to address all the issues we currently face.
Some problems can grow exponentially and would take classical computers decades or more to solve. For instance, the algorithm we use for encryption is vulnerable to quantum attacks. Other challenging problems include optimization, chemistry simulation, and machine learning.
Researchers are shifting to quantum computing to address these challenges more effectively, which uses quantum bits or qubits. As to execute specific sorts of operations much faster than classical computers can.
The five core elements of a quantum computer/quantum computing
- Superposition
- Measurement
- Gates
- Interference
- Entanglement
Superposition:
Unlike classical computers, which use binary bits to represent either 0 or 1, quantum computers use qubits. Qubits can be in a superposition and they can exist in a range of states. It can be any linear combination of 0 and 1. This superposition of states allows quantum computers to perform certain types of calculations. These calculations are much faster than classical computers.
Measurement:
When a qubit is measured, its superposition state collapses into either a 0 or 1 state. This collapse is probabilistic, so a qubit in superposition doesn’t represent a value of 0.5. But it has a probability of 50% to collapse into a 0 and a 50% chance to collapse into a 1. This probabilistic nature is what people mean when they say a qubit may be both 0 and 1. The exponential increase in the number of states that a quantum system may represent also means that a tiny number of qubits can represent a tremendous quantity of data.
Gates:
To perform calculations with qubits, we use gates that can manipulate the state of a qubit. Similar to classical computers, we can string together qubits with gates to create quantum circuits. For example, we can use the Hadamard gate (H gate) to put a qubit into a superposition between 0 and 1. Quantum circuits can include multiple qubits and gates, and to obtain useful results, we need to read the outputs of the circuit at some point.
Interference:
The main advantage of quantum computers is to perform parallel computations. This is achieved through the use of quantum states. By applying an operation to the quantum state, we can simultaneously perform two calculations at once, leading to a significant speedup in certain types of problems. However, the collapse of a qubit’s superposition into a single state upon measurement presents a challenge. To get a correct answer, the quantum gates must be arranged that amplifies and cancels out all the incorrect ones. This process of quantum error correction is critical for the reliable operation of quantum computers. A process called interference.
Entanglement:
States of entangled qubits exhibit substantial correlations. Changing the state of just one qubit would, therefore, affect the state of all the others. We can, for instance, entangle two qubits so that their states are equally likely to measure a 00 and an 11, but never a 01 or a 10. In this situation, if we only changed one’s condition, the other one would also change. The combined strength of superposition, interference, and entanglement allows quantum computers to tackle problems that are now incomprehensible to conventional computers
Conclusion
Quantum computing is a developing field of computer science. It is mainly focused on using the principles of quantum mechanics. These computers are fundamentally different from classical computers. How they process information, and they have the potential to solve certain problems much faster than classical computers can.