The Fast-moving Technology of Quantum Computing


Peet van Biljon shares a recently published article on quantum computing in finance.

There are two competing narratives on quantum computing. The first is that the technology is overhyped, still in its infancy, beset by enormous technical challenges and that full-scale, reliable quantum computers are decades away. The second is that many companies, including some of the world’s most prominent financial institutions such as Barclays, BBVA, JPMorgan, Goldman Sachs and RBS are investing in, and experimenting with, quantum-computing applications and that business impact can be expected in the near term.

Which narrative is the correct one? Perhaps surprisingly, both are true. That creates an urgent need for finance leaders to understand the technology better in order to discern the short- versus medium-term implications for their companies, and to shape a viable quantum-computing strategy.

The information revolution of the last few decades was built on our ability to miniaturise transistors. In modern digital computers, now called classical computers to differentiate them from quantum computers, billions of little transistors switch on and off to execute binary logic. At the lowest level, a logical bit can either be a 1 (the transistor is on) or a 0 (the transistor is off).

Quantum bits, called qubits, are encoded and measured in two equivalent binary states called |0> or |1>, which are usually associated with the up or down spin of an electron. However, two strange properties of quantum mechanics, called superposition and entanglement, allow qubits to take on a continuum of non-binary values and interact with one another in that state to perform calculations. Any measurement collapses superposition, which means that the only two states a qubit can be measured in is either |0> or |1>.

While in superposition, qubits can be manipulated to process exponentially more information than classical bits. In fact, n qubits can process the same information as 2 to the power of n classical bits. When quantum computers eventually scale to hundreds of usable, error-corrected qubits, 2 to the power of n will become a truly astronomical number, allowing more calculations than classical computers can ever do. This explains the excitement about quantum computing technology.


Key points include:

  • The processing power of quantum computing technology
  • Managing qubits’ decoherence
  • translate real-world finance problems into quantum computing algorithms


Read the full article, Closer than you think – quantum computing in finance, on