Quantum Computing has been the heart of many research work and applications so much so that in recent years organizations in several countries have devoted significant resources to its development. Quantum technologies have strategic implications for this globalized world, reaching different institutions including the government since they present not only challenges for decisionmakers, but also many practical implications for individuals’ lives.
Although Quantum Theory is nothing new and we may encounter some notions in the philosophical doctrine in dealing with the processes and events in physics, it is only natural for many of us to view the language and the logic of quantum theory as unfamiliar as it was the notion of an atom when it was first worded.
Discussions on the crucial happenings of the quantum theory are dated back to 1900 when physicist Max Planck presented his quantum theory to the German Physical Society. Later, and probably most will relate the theory to Albert Einstein, who saw Quantum Theory as a means to describe Nature on an atomic level, in other words, it proposed that energy exists as discrete packets—each called a “quantum”, a notion challenged by Niels Bohr, also considered a Quantum Theory founding father.
Quantum computing focuses on the principles of quantum theory such as quantum bits, superposition, and entanglement to perform data operations, allowing computers to essentially tackle extremely difficult tasks that classical computers cannot perform on their own.
So, let’s start with some basics, shall we?
“In the history of science, a new concept never springs up in its complete and final form as in the ancient Greek myth, Pallas Athene sprang up from the head of Zeus”, said Max Planck in one of his lectures on the development of physics. This statement poses clearly that the history of physics is not only a sequence of experimental discoveries and observations, followed by their mathematical description; it is also a history and development of concepts.
Therefore, for understanding a phenomenon the premise is to introduce adequate concepts.
What does a qubit mean?
In simple terms, “a qubit (or quantum bit) is the smallest unit of information analogue of a classical bit. In classical computing the information is encoded in bits, where each bit can have the value zero or one. In quantum computing the information is encoded in qubits.
A qubit is a two-level quantum system where the two basis qubit states are usually written as |0> and |1>. A qubit can be in state |0>, |1> or (unlike a classical bit) in a linear combination of both states.
What are the quantum properties?
The special properties of quantum objects (atoms, ions, and photons) are superposition, interference, and entanglement.
Quantum superposition is a fundamental phenomenon of quantum mechanics where two or more quantum states can be added together “superposed,” and the result will be another valid quantum state. The corollary of this is that every quantum state can be represented as a sum of two or more other distinct states (Termanini, 2020). Following Swan, dos Santos and Witte (2021) “superposition refers to particles existing across all possible states simultaneously”.
Quantum Interference is the situation where intervention from noise in the environment damages the quantum object, and also the possibility that the wave functions of particles can either reinforce or diminish each other. (Swan, dosSantos, Witte, 2021).
Quantum entanglement is a physical phenomenon when several particles are grouped together, so the quantum state of each particle cannot be described independently; instead, a quantum state is described as a whole. (Termanini, 2020). According to Swan et al (2021): “entanglement means that groups of particles are connected and can interact in ways such that the quantum state of each particle cannot be described independently of the state of the others even when the particles are separated by a large distance.”
Expressing it an understandable way, when the qubit is simultaneously a one and a zero, it is said to be in a state of superposition. The state of one qubit can influence another qubit, even if they are separated by great distance, in this case, the states are said to be entangled.
Superposition and entanglement are properties that can accelerate multitudes of calculations at once, theoretically. The fact that qubits can be entangled, makes a quantum computer more powerful than a classical one. Also, with information stored in superposition, some problems can be solved exponentially faster.
What about Quantum Computing use cases?
Many companies are taking the first steps in providing QCAAS. Focusing mainly on optimization, research and cryptography, companies such as JP Morgan, Goldman Sachs, IBM, Google, Microsoft, to name just a few, are testing quantum systems for their optimization challenges.
Here are some of the use cases, where QC is applied to different fields:
• Healthcare and Pharma: Drug interaction prediction and personalized medicine
• Chemicals and Petroleum: changing how chemicals are designed and petroleum is refined and located
• Finance: automated trading, risk analysis, portfolio optimization, and fraud detection (Braña et al 2018, 2019, Litterio, 2019)
• Insurance and Logistics: valuation of instruments, premiums in complex cases, supply change and inventory optimization
• Farming and agriculture: optimization of logistics, scheduling, supply chains, finance, managing networks of farming communities and so on. (Srivastava 2021)
Source: Mckinsey
Last but not least, what is the timeline for quantum applications?
According to IBM, there are three maturity horizons where uses cases are to evolve
• Horizon 1: Applications in the next years
• Horizon 2: After stable but not optimally working quantum computers
• Horizon 3: 15 years and beyond
Source: IBM
It can be said that Quantum Computing is still a nascent technology. And there is much more to come to build “quantum fluency”.