Quantum computing is a multidisciplinary field of computer science, mathematics, and physics that harnesses the unique qualities of quantum mechanics to solve problems beyond the ability of even the most powerful classical computers.
The potential quantum computing holds is unparalleled. Unlike classical computers that operate on the binary system of 0s or 1s, quantum computers utilize quantum bits, or qubits.
Qubits, based on principles of superposition and entanglement in quantum mechanics, can exist in multiple states simultaneously (superposition), and two or more qubits can be manipulated in a single operation (entanglement). Meaning a qubit can be a 0 or a 1, but can also exist as 0 and 1 at the same time.
This allows them to perform calculations exponentially faster than their classical counterparts, particularly for certain complex problems. Following this principle, 2 qubits can process 4 pieces of information, 3 qubits can process 8 pieces of information, and so on.
How does Quantum Computing work?
Quantum computing functions on four basic principles, which include:
- Superposition, a state where a qubit can exist in two different states or possibilities at the same time.
- Entanglement, which allows two or more qubits to interact and be manipulated to give results.
- Decoherence, the state where qubits lose their ability for superpositioning and entanglement due to environmental disturbance. This can be triggered intentionally, as it allows quantum computers to provide measurements and interact with classical computers.
- Interference, the ability of qubits to overlap and interact with each other, which aids the algorithm behind quantum computing.
Qubits are made from trapped ions, photons, artificial or real atoms, or quasiparticles. Qubits, however, are very susceptible to interference from external factors like temperature, light, and sound, which can affect the results of the quantum computer.
To effectively make use of qubits in quantum computing, the qubits are kept at a cryogenic temperature of the lowest absolute zero to help reduce thermal noise, preserve the quantum states of the qubits, and reduce the risks of decoherence.
Qubits come in various forms, each suited for different types of tasks. In a non-exhaustive list of qubits that have been proposed/implemented, the commonly known ones include:
- Superconducting qubits: this is a commonly used qubit in quantum computing. It is based on the Josephson junction, a device that allows the flow of supercurrent without resistance. It is made from superconducting materials that operate at low temperatures to store and process quantum information and is favored for its speed in performing computations and fine-tuned control. Examples include flux qubits and phase qubits.
- Trapped ion qubits: makes use of charged atoms/ions that are confined and manipulated in free space by electromagnetic fields, causing their quantum states to serve as qubits. Calcium, magnesium, and beryllium ions are used for this purpose.
- Quantum dot qubits: qubits are generated from the quantum states of electrons confined in semiconductor dots. They are manipulated using electrical gates and magnetic fields.
- Topological qubits: quantum information is stored on the topological properties of a material rather than in individual particles. Qubits of this form are considered potentially more stable and less error-prone.
- Diamond nitrogen vacancy (NV) center bit: makes use of the quantum state of an electron trapped in a diamond-like lattice to store and manipulate information. This qubit form is manipulated using microwaves and optical fields. It is effective in fields like quantum sensing and metrology.
- Nuclear magnetic resonance (NMR) qubits: utilizes the quantum states of atom nuclei with molecules as qubits by manipulating the nuclei using radiofrequency pulses in a magnetic field. It is commonly used in quantum chemistry simulations.
- Photonic qubits: leverages the quantum properties of light, using beam splitters, phase shifters, and detectors to represent and process quantum information.
To input information into a quantum computer, the data is encoded into qubits using different encoding methods like basis encoding, amplitude encoding, or angle encoding (among others), all dependent on the information type and quantum algorithm being used, for example, Grover’s algorithm for amplitude amplification, quantum simulation algorithms, hybrid quantum/classical algorithms, and so on.
The output from a quantum computer is in the form of classical bits of 0s and 1s, which is then processed and interpreted to obtain desired results.
Uses of Quantum Computing
Below are key areas where quantum computing has had/is playing impactful roles:
- Pharmaceuticals: Quantum computers can stimulate molecular behavior and biochemical reactions with unprecedented accuracy when developing a new drug, catalyst, or advanced materials. This speeds up the research rates and development of life-saving drugs and treatments.
- Machine learning: Quantum algorithms can accelerate machine learning tasks, such as data analysis and pattern recognition, which can lead to more advanced AI systems.
- Material science: Quantum computing can stimulate a quantum system to better understand properties of materials at atomic and molecular levels.
- Finance models: Due to the speed, accuracy, and ability of quantum computers to carry out complex analysis, it allows the computer to be suitable for valuation of products and credit risk assessments.
- Meteorology: uses quantum theory to make high-resolution and highly sensitive measurements of physical parameters of the weather to make accurate forecasts.
- Other uses of a quantum computing system include cryptography, traffic optimization, quantum sensors, and solar capture.
Quantum computing is a system that is already in play in some high-tech industries, national labs, and universities for research and application purposes. IBM (International Business Machines Corporation) uses and develops quantum computing for financial models, quantum-centric supercomputing, and developing quantum-resistant encryption technologies.
Microsoft’s Azure Quantum Compute platform is used for scientific research, material science, and drug discovery. Rigetti Computing produces quantum processors for chemical stimulation, combinatorial optimization, and machine learning.
JPMorgan Chase is currently working on building new quantum algorithms and applications for finance models, machine learning, and cryptography. Google employs the use of quantum computing for research, logistics, financial modeling, and supply chain optimization. Volkswagen AG optimizes quantum algorithms for traffic routing and financial modeling.
Quantum computing is no longer an object of fantasy. It currently stands as a revolutionary technology in its infancy and is currently making strides in recent applications. The current strides and future predictions regarding this tech are too significant to ignore, and with further research and innovations, this technology will cross borders of the “hype” about it.
