While the world of quantum computing is advancing at a rapid pace, having a quantum computer in your home for everyday use is still a very distant prospect, likely decades away, if it ever becomes a reality in the way we think of personal computers today.
The fundamental nature of quantum computers makes them unsuitable for the tasks you’d typically use a home computer for, such as Browse the internet, sending emails, or word processing.1 Instead, they are designed to tackle complex calculations that are far beyond the capabilities of even the most powerful classical supercomputers.2 These applications include drug discovery, materials science, financial modeling, and breaking complex cryptographic codes.
Currently, quantum computers are massive, specialized machines that require extreme conditions to operate.3 Here’s a breakdown of the primary obstacles preventing the development of at-home quantum computers:
Size and Infrastructure
Today’s quantum processors are housed in large dilution refrigerators, which are multi-stage cooling systems that bring the quantum chip down to temperatures colder than deep space, typically around -273 degrees Celsius (close to absolute zero).4 These refrigerators are bulky, expensive, and consume a significant amount of power.5 The supporting electronics required to control and read out the quantum information also take up considerable space, often filling an entire room.6
Extreme Cooling Requirements
Quantum bits, or qubits, the fundamental building blocks of quantum computers, are incredibly fragile.7 They are highly susceptible to environmental “noise,” such as vibrations, temperature fluctuations, and electromagnetic fields.8 This noise can cause the qubits to lose their quantum properties in a process called decoherence, which leads to errors in calculations.9 The extreme cold is necessary to minimize this environmental noise and maintain the delicate quantum states of the qubits for as long as possible.10
Error Correction
Due to their susceptibility to errors, a significant number of physical qubits are required to create a single, stable “logical qubit.”11 The overhead for quantum error correction is immense, meaning that a useful, fault-tolerant quantum computer will likely require millions of physical qubits. We are currently in the era of “Noisy Intermediate-Scale Quantum” (NISQ) devices, which have hundreds to a few thousand physical qubits and are not yet fault-tolerant.12
The Rise of Cloud Access
For the foreseeable future, the primary way for individuals and businesses to access the power of quantum computing will be through cloud-based services.13 Companies like IBM, Google, and Amazon are already providing access to their quantum computers via the cloud.14 This model allows researchers and developers to experiment with quantum algorithms without needing to own and maintain the complex hardware themselves. A recent development known as “blind quantum computing” even allows for secure access to these remote quantum computers, ensuring the privacy of the user’s data and computations.15
The Long-Term Vision
While some researchers are working on developing smaller, “portable,” and even “room-temperature” quantum computers, these are still in the very early stages of development and are primarily intended for educational and research purposes. They have a very limited number of qubits and cannot perform the complex calculations that larger quantum computers are being built for.
The long-term vision for quantum computing is not necessarily a personal quantum computer in every home. Instead, it’s more likely that classical computers will continue to be our primary personal devices, with the ability to seamlessly access the immense power of remote quantum computers via the cloud for specific, complex tasks. Therefore, while you may one day use a quantum computer from the comfort of your home, it’s highly improbable that you’ll have a physical quantum computer sitting on your desk.
