Comments about the article in Nature: How to introduce quantum computers without slowing economic growth

Following is a discussion about this article in Nature Vol 619 20 July 2023, by Chander Velu & Fathiro H.R. Putra
To study the full text select this link: In the last paragraph I explain my own opinion.




The breakthroughs they promise — new ways of simulating materials, optimizing processes and improving machine learning — could transform society, just as today’s digital computers have done.
The main problem is that the physics involved i.e., quantum mechanics, the study of elementary particles, contains many uncertainties.
The quantum computing revolution could be much more painful.
Probably true.
Quantum computers operate in a completely different way from digital computers, and can potentially store and analyse information more efficiently.
This still contains a risk.
Quantum computers encode information in the quantum state of atoms, electrons and photons, known as qubits. These qubits can represent many states at once and be combined or 'entangled’, thereby speeding up calculations.
That is theoretical a correct description, but contains a big if, if this physical goal can be reached in reality.
However IMO the biggest problem is to convert a physical process into QC logic, which can be implemented onto a QC, and be solved.
A simpler path to go is to start with a mathematical problem, but that limits its application space.
When digital computers started to gain popularity in the 1970s and 1980s, rather than delivering efficiencies, for 15 years they slowed growth in productivity, the value added relative to inputs such as labour, by 0.76 percentage points per annum.
We think that the quantum computing revolution could lead to an even more severe and expensive learning curve, for three reasons:
  1. high integration costs and few short-term rewards;
  2. difficulty in translating quantum concepts for business managers and engineers;
  3. and the threat to cryptography posed by quantum computers.
Fortunately, there are ways to lighten the load and accelerate the benefits to society, three of which we outline here.
I'm pessimistic if quantum computers have benefits for all of us.

1. Demonstrate the value of quantum computers for societal challenges

Firms might initially adopt quantum computers to solve existing business problems, for which improvements are likely to be incremental. But for more-ambitious uses, the extra costs and likelihood of potential failures might make firms risk-averse.
For example, a company that collects vast amounts of data from sensors to inform disaster relief and recovery might look to quantum computers to process information more quickly, to help save lives.
When a disaster is in progress and lives are at stake, you need a rescue team, with experience and gouvermental support, to cross borders. I doubt if QC's will be of much help.
But the first such computers might be more prone to faults and errors than are digital ones, with potentially grave consequences for life-critical operations. Such companies might therefore be put off from using quantum computers, until they are more reliable.
The problem with quantum computers is that they work with propabilities. That means the result, based on the same data, is not always the same. Digital Computers don't work with probabilities. The answer is always the same. I can not estimate the severity of this problem
Firms will still need digital computers to perform everyday tasks and computations; they will use quantum computers to solve more-complex and specialist problems.
Remember, my expectation is, to solve complex computers on a QC, will be very tricky. Start simple.
Yet, developing hybrid protocols and programs that can work in both situations is much harder than it was to program digital computers in the 1970s.
In the 1970s the problem was related to Analog Computers versus Digital Computers.
The Analog Computer was, for example, used to simulate one specific airplane. The air plane was simulated as a set of differential equations.
The Digital Computer was used to set up the initial conditions of each run and the individual parameters.
The special interface between the DC and the AC to convert digital signals into analog signals and the reverse between the AC and the DC creates what is called a Hybrid Computer.
Hybrid systems will need to be fluent in both digital bits and quantum qubits, and able to encode classical data into quantum states and vice versa.
Hybrid systems in 2023 are a combination between a Quantum Computer and a Digital Computer. The QC is based around qubits. The DC is based around digital bits.

2. Agree on a common language and build understanding

Quantum technologies operate on principles that are often counterintuitive and outside the comfort zone of many engineers and business managers.
They should not be outside the comfort zone of physicists. Physicists should 100% agree on the principles Quantum computers are based upon.
For example, these technologies work probabilistically and don’t seem to obey classical conceptions of cause and effect.
We live in one world. It is wrong to speak of a classical world versus a quantum world. Every photon or neutrino that reaches the earth has an origin, is caused by something else in the past and is surrounded by a cloud of uncertainty.
According to some schools of thought, in the quantum world, human agency might influence outcomes, meaning the person operating the computer might need to be considered as part of the system.
I would like to ask the authers of this text (Heisenberg?) to explain what they mean.
We don't live in a quantum world. We humans are situated somewhere in the universe. The universe, enlarge, consists of objects based out of elements (atoms) and molecules. Humans, in general, are in no way, involved in the evolution of the universe.
Managers and engineers will need to know enough to be able to select the right class of problems for quantum computers, know what type of information is required to solve them, and prepare data in a quantum-ready format (see or: ).
This is a very complex technical problem, which involves training.
For example, a delivery logistics company might wish to reschedule its vehicle routes more rapidly to respond better to customer demand for pickups of goods that need returning.
The question is simple, the answer can be difficult. The overall issue is, if it is possible.
Quantum computation could be effective for such replanning — which involves solving a complex combinatorial problem — in which one change has a knock-on effect on other areas of the business, such as inventory management and financing.
Could be.
But managers would need to be able to spot areas of advantage such as this and know what to do to implement quantum computing solutions.
You need qualified engineers, not managers.
A common semantic and syntactic language for quantum computers needs to be developed.
The question is easy . The actual solution is complex .
It should be similar to the standardized Unified Modeling Language used for digital computer programming — a visual language that helps software developers and engineers to build models to track the steps and actions involved in business processes.

My overall impression is, that in order to write a usefull program, much more detailed information is requiered.

Such a tool reduces the costs of software development by making the process intuitive for business managers.
Some people believe in dreams.
Quantum computers also require algorithms and data structures, yet quantum information is much richer than classical information and more challenging to store, transmit and receive.
First you must now exactly know, what an algorithm for a QC is.
My impression is that the logic behind an algorithm for a QC is something completely different than the logic behind an algorithm for a DC.
The logic behind a DC is sequential. To get an idea select this link:
A quantum unified modelling language that is similar to the classical one but can also work with quantum information will enable scientists, engineers and managers to stay on the same page while they discuss prototypes, test beds, road maps, simulation models and hybrid information-technology architectures
My impression that you need a complete new language and complete change of mind to use a quantum computer.
Strategies for communicating about quantum computing with the public are also needed, to build trust in these new technologies and ensure that benefits accrue to all parts of society in a responsible manner.
To build trust you need an easy to explain example that shows the advantage of a Quantum Computer versus a Digital Computer.
That is not easy

3. Build a quantum internet with secure encryption

Reflection 1 - The physics behind Quantum Computers

Reflection 2

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Created: 1 September 2023

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