When will we have quantum laptops?

Quantum computers are here. But can we build a quantum laptop?

About 80 years ago, scientists in England, Germany, and the United States quietly researched and built the first electronic computers. These giant machines were the size of an entire room, consumed enormous amounts of energy, but opened a new era of unprecedented computing power.

At the time, few could have imagined that, just a few decades later, much more powerful computers would be small enough to fit in a backpack. However, that has happened, and the question now is whether we will one day see the emergence of quantum laptops.

Potential and future predictions

In the past, computers were the size of a room.

Quantum computing researcher Mario Gely of the University of Oxford says that owning a quantum laptop is possible, although it remains highly speculative. 'I can't think of any fundamental reason why it wouldn't be possible,' Gely says . But before that vision can be reached, scientists will need to overcome some major hurdles in developing quantum technology.

Stephen Bartlett, director of the Nano Institute at the University of Sydney and a theoretical physicist specializing in quantum computing, believes we could see truly useful quantum computers within this decade. However, he also notes that many scientific challenges remain open and unsolved. 'The path is still quite obscure, but we are getting closer ,' Bartlett said.

Qubit Scaling: The Key to Unlocking New Doors

Before thinking about quantum laptops, the first thing to do is to create a truly useful quantum computer , that is, a device capable of solving complex problems that current supercomputers cannot handle. The main challenge lies in the number of qubits – the basic unit of quantum computing, equivalent to digital bits in classical computers. Currently, the number of qubits in systems is still limited and needs to be increased many times to meet the requirements of truly powerful quantum computing.

Scientists have made significant progress, such as quantum charge-coupled device (QCCD) architectures. QCCDs enable two-dimensional qubit arrays, which increase qubit density and open up the possibility of more efficient scaling. However, the path from current research to a truly practical quantum computer is still long and challenging.

The need for different types of qubits

Current quantum computers, such as those developed by IBM and Google, rely heavily on superconducting qubits. However, the technology has a major limitation: superconducting qubits only work at extremely low temperatures , close to absolute zero (about 20 millikelvin). Maintaining these temperatures requires the use of giant dilution refrigerators, which take up a lot of space and consume a lot of energy. IBM's goal in its quantum computing roadmap is to create a computer with 2,000 qubits by 2033, but that would still fill a large room.

Current quantum computers like those developed by IBM and Google.

So to make the dream of a quantum laptop a reality, scientists need to explore other types of qubits. One possible option is the trapped ion qubit. These qubits are made of charged particles that can exist in multiple states at once, held in a state of suspension by an electromagnetic field. Unlike superconducting qubits, trapped ion qubit systems operate at room temperature and do not require large refrigerators.

The biggest challenge for ion qubits, however, is the accompanying laser system . Currently, these systems take up up to a cubic meter of space. 'If we consider ion traps to be the future, we need to make these laser systems compact ,' Gely said. Lasers not only need to be smaller, but also need to be improved to be able to handle large numbers of qubits. Current systems can only control up to 100 ions, which is not enough to create a full quantum computer with millions of qubits.

Recent developments

While many challenges remain, recent advances have offered hope. QCCD architectures promise to increase qubit density, while breakthroughs have been made in reducing the size of laser devices. In July, researchers at Stanford University developed a new titanium-sapphire laser that is 10,000 times smaller than previous lasers. This improvement could dramatically reduce the size of trapped ion qubit systems.

Bartlett is also optimistic that hardware miniaturization and optimization are not impossible. While there are still many unknowns, he believes challenges like error correction and scaling up the number of qubits will be overcome in the future. The bigger question, however, is whether quantum laptops will actually benefit mainstream consumers.

 Whether quantum computers will ever be widely used is still a big question mark.

Applications and perspectives of quantum laptops

Even if the technical issues are solved, it remains a big question mark over whether quantum computers will ever be widely used. Gely suggests that instead of replacing classical computers entirely, quantum laptops could be integrated as an auxiliary processor, similar to the graphics cards in today's computers. "It could be useful for some specific tasks, but not for everything ," he says.

Bartlett also emphasized that applications of quantum computing will likely focus on areas such as finance, information security, or other niche applications. However, no one can yet predict exactly how quantum computing will change everyday life.