Researcher in a deep tech startup explains the state of quantum computing

To gain a deeper understanding of quantum computing and its potential impact on modern technology, we spoke with Radoica Draskic, a researcher at NextSilicon. He provided valuable insights into the principles of quantum computing, its current development, and its profound implications for various industries, from cryptography to complex system simulations.

Radoica: Quantum computing is a fascinating and relatively young field that uses the principles of quantum mechanics to build a new type of computer system. Quantum computers differ from traditional computers primarily in how they store information.

They use qubits, the analog of a bit in a classical computer, but with the added ability to exist in a superposition of states. This means they can represent many different states simultaneously during calculation, unlike classic bits that can only be 0 or 1.

In practice, qubits inherently manipulate probabilities and collapse their state into 0 or 1 at the end of a calculation with a certain probability. This superposition, together with quantum entanglement (a phenomenon in which qubits are interconnected so that a change in the state of one qubit affects the state of another, regardless of distance), enables quantum computers to solve complex problems faster than classical computers.

How reliable are quantum systems today?

Radoica: Today’s quantum computers make many errors, and their current form raises questions about their readiness to perform the desired calculations accurately enough. This issue partly arises from the inherent instability of qubits, which environmental changes, such as temperature, radiation, and even cosmic particles, can affect.

Therefore, experts in the field work on various solutions to reduce the impact of errors, including developing sophisticated quantum algorithms for error correction and researching new materials and designs to stabilize qubits.

For example, a team of researchers at Microsoft works on developing so-called topological qubits. These qubits use physical principles different from those of other popular hardware platforms, such as superconducting qubits, and researchers expect them to be less susceptible to harmful environmental influences.

Some proponents argue that quantum computers will never be practical because correcting all the errors during the calculation will require so many resources that the algorithm will not execute in any reasonable amount of time.

However, it is essential to note that this remains a very active area of research, and many of these questions still need full resolution.

Quantum computers have the potential to break commonly used cryptographic systems. How can data be protected?

Radoica: Shor’s algorithm for factoring numbers, one of the most influential algorithms in the development of the entire field, could theoretically break many of today’s cryptographic systems. Given the possible ability of quantum computers to break modern cryptographic systems, researchers are developing post-quantum cryptography with great interest.

This field focuses on creating new cryptographic algorithms that resist quantum computer attacks. These new algorithms rely on mathematical problems that quantum computers cannot penetrate, such as various problems on periodic lattices.

Although post-quantum cryptography shows promise, it remains a young discipline, with many aspects still under intense research.

In situations where specific sensitive data exchanged today must stay secure even decades from now when sufficiently powerful quantum computers might exist, researchers are heavily investing in developing the quantum internet.

Like quantum computers, the quantum internet uses qubits instead of bits for communication. Due to quantum entanglement, users can securely exchange cryptographic keys, which would avoid many problems associated with “classical” cryptography.

Companies such as Google and IBM have achieved dominance in this area. What’s next?

Radoica: Several companies and institutes worldwide have successfully conducted the quantum supremacy experiment, the most famous being Google’s 2019 experiment. This experiment involved a specially constructed random number generation algorithm that is difficult to reproduce without a quantum computer.

The algorithm itself has only practical use to demonstrate the technology’s maturity and the potential of quantum computers to solve problems beyond the reach of classical computers.

To carry out that experiment, researchers needed to develop a quantum processor with a sufficiently large number of qubits, systems for combating the harmful influence of the environment, and mathematical and software tools for processing the results.

These advancements have already marked exceptional progress. Those results motivated researchers to create processors with even more qubits, which could solve more industrially applicable problems, such as designing new materials.

One of the biggest challenges in quantum computing is increasing the number of qubits. How do researchers deal with it?

Radoica: About twenty years ago, researchers successfully realized systems consisting of several qubits. However, increasing the number of qubits has emerged as one of the most significant challenges since then. The key issues vary slightly between different hardware platforms.

For example, the currently most popular superconducting qubits face a substantial limitation in establishing communication between the qubit and the classical electronics that orchestrate its behavior.

This necessity results in an explosion in the required wires, and various research groups are exploring different approaches to address this. Another issue is that after lithographically printing the quantum chip, researchers must characterize it, meaning they must measure all relevant parameters and bring the chip into a mode where it can stably perform calculations.

This task becomes increasingly complex with increased qubits and often requires expert intervention. Therefore, researchers are making significant efforts to automate and parallelize the process.

Another challenge is that superconducting quantum chips must be stored at very low temperatures, according to Millikelvin, and chips with a more significant number of qubits require larger cryostat.

Quantum computing is very interdisciplinary. What experts are involved?

Radoica: Quantum computing involves elements of physics, mathematics, computer science, and engineering, making it a profoundly interdisciplinary field. Physics, primarily quantum mechanics, provides the theoretical framework for quantum computing.

Mathematics and computer science help develop algorithms that effectively utilize quantum computers’ capabilities. Engineering plays a crucial role in designing and constructing quantum computer hardware.

These fields are closely intertwined, and experts often possess knowledge across multiple aspects of quantum computer development. For instance, in recent research aimed at demonstrating the utilization of current quantum computers, most participants need to understand various levels of abstraction, from hardware features to the complexities of the mathematical computations to be executed on them.

Do you apply the principles of quantum computing in your daily work?

Radoica: I am a researcher at NextSilicon, where we are building a new generation of hardware accelerators. Although I am not directly involved with quantum computers, my involvement in science has helped me approach problem-solving analytically in my daily work and be more effective. There are many similarities between the vision of quantum computers and what NextSilicon aims to achieve using existing hardware technologies.

What attracted me are the speedups that NextSilicon is achieving today while quantum computers are still in the early stages of development.

How do you stay updated with trends and the latest technologies significant for your work?

Radoica: One of my most significant daily sources of information is my connections on social networks and the pages of companies and institutes dealing with quantum computing. Additionally, I regularly follow the latest preprints of scientific papers by searching for keywords in this field and following several researchers whose research areas interest me.

Moreover, numerous lectures and seminars from popular conferences are shared on YouTube shortly after the events.

I also follow several open-source projects for various frameworks for programming quantum algorithms and communicating with quantum processors. As an individual, this is one of the most essential sources for me, considering that it is sometimes challenging to reproduce the latest results in the field independently.

What, in your opinion, are the most promising applications of quantum computing in the short term?

Radoica: One of the most promising quantum computer applications will be chemical and physical calculations. Speeding up those calculations would revolutionize the development of new materials and drugs.

Quantum computers have a great chance of success in these areas because the behavior of electrons in molecules can be naturally described by qubits, and the chemical and physical properties of molecules largely depend on their electronic structure. Several researchers are also trying to speed up key algorithms in machine learning and finance.

However, in my opinion, the real breakthroughs in those areas will happen a bit later due to the need for more qubits and the creation of more levels of abstraction to hide the painstaking implementation of mathematical calculations over quantum registers.

Also, Shor’s algorithm will likely have to wait for a better moment. Still, if the development of the quantum internet happens by then, it will likely no longer be overly attractive to anyone in the context of secure communication. Even so, it will be a crucial routine in many other quantum algorithms.