DEGGENDORF, GERMANY - In recent years, many have heard of quantum computing (QC) and some of its hyped capabilities such as ‘super-fast computers.’ Most, however, do not understand how this technology works and what challenges are involved when implementing large-scale quantum computers. This article will explore some of the core concepts of QC and its potentials and discuss why they will probably remain in niche applications in the foreseeable future.

QC’s Promise

Traditional computers are made of bits, whose states are either 0 or 1. A bit is a switch turned on or off, or whether electricity travels through a circuit or not. This resembles an understanding of our environment and classical physics. In quantum theory, however, a tiny particle, such a photon or electron, can be in multiple locations at the same time. This concept is called ‘superposition’ and confuses most people at first sight. The idea of QC is to take advantage of quantum physics for a new computational paradigm. Quantum computers are made of quantum bits, or qubits in short, that can be in states 0 and 1 in parallel thanks to superposition. By combining multiple qubits, a quantum computer can then be in a superposition of a large number of states. QC thus has the potential to solve certain computational optimization problems substantially faster because of the resulting quantum parallelism.

QC Influence in the US and Europe

The theory of QC began in the 1980s but most of today’s theoretical foundations were published in the 1990s. Early quantum computers of the US-based company D-Wave have been available since 2011. D-Wave uses a simplified QC model called ‘quantum annealing.’ While that model has received criticism for being limited, it is the most practical approach that already works today. The first D-Wave quantum computer outside the US was installed in 2019 a