have 1,000 usable Qubits once error correction using redundancy principle is taking into account. So the end goal for Quantum Computing is to improve the stability of the Qubits and have a Quantum Universal Computer that can handle any algorithm – which realistically is still a good 10-15 years in the future (see fig.2)
Fig.2 Source. Michel Kurek, Feb 2021.
Does that mean we wait 15-20 years to play with Quantum Computers?
No. The industry is learning to live with the current deficiencies and are implementing NISQ (Noisy Intermediate-Scale Quantum) technologies. Basically this means they are developing algorithms that can be deployed on the basis that there will be some errors which can be accounted for OR they are using a combination of quantum and classical computing.
Companies like Atos Quantum have developed emulators that simulate a 50 Qubit Quantum Computer. You can also set the fault tolerance for the Qubit in the simulator to give you a realistic result based on todays machine.
Uncluttered by the computational constraints of todays infrastructure, there is also a new branch of Quantum Inspired Algorithms which can be tested on these simulators.
Is anybody using this in finance?
Yes, there are several banks that are partnering with the IT monoliths or startups or directly investing in Quantum Computing. The obvious use cases in financial services are based around Portfolio Optimisation, Quantum machine learning (being able to train a model in a fraction of the current time with much larger datasets) and modelling (JP Morgan completed a proof of concept for option pricing) https://arxiv.org/pdf/1905.02666.pdf
The advantages of being able to run vast computations in very short time periods are obvious.
Out of the c.100 industry partners working with IBM ‘s Quantum Computers, 7 are financial services firms including JP Morgan, Barclays, Goldman Sachs and Wells Fargo. Overall there are currently 20 financial institutions in the quantum ecosystem.
Goldman Sachs and Citigroup are also investing directly in Quantum Computing companies like D-Wave and QC ware.
How to run an algorithm on a Quantum Computer
Whereas D-wave is actually selling their machines, most big IT firms are taking a cloud utilisation model, QaaS : Quantum as a service, which is enabling a lot more companies to experiment with the technology.
There is apparently over 50 different programming languages that are being run on Quantum Hardware. Most big vendors have developed their own languages which syntax is pretty much like Python however Microsoft, being Microsoft, developed a language called Q#. A good summary can be found at https://quantumcomputingreport.com/wp-content/uploads/2018/06/Overview-and-Comparison-of-Gate-Level-Quantum-Software-Platforms-Final-June-21-2018.pdf
The industry is really going to be driven by effective use cases for the technology so free access to emulators and or direct access to quantum computers is available.
As the practical applications of Quantum Computing increase so will investment and eventually adoption.
So, to sum up, Quantum Computing is not quite there yet however it is coming and it will have a massive impact. Bearing in mind there are simulators out there, if you were given a quantum computer tomorrow – what could you do better?
Michel is the ex Head of Algorithmic Execution at Societe Generale and now a member of Lab Quantique (a Paris based Think Tank) and the QuantX Group at Ecole Polytechnique (a group focused on the field of Quantum Technologies).