In recent years, news about general-purpose quantum computers has frequently appeared in the media. Companies such as IBM, Google, and Intel have been vying to announce that they have achieved higher records for the number of qubits. However, if dozens or even a large number of qubits cannot be fully interconnected, the precision will be insufficient and errors cannot be corrected, making general-purpose quantum computing still difficult to achieve.
In contrast, simulated quantum computing can immediately build quantum system software without relying on complex quantum error correction. As a powerful algorithmic core of simulated quantum computing, quantum movement in two-dimensional space can map specific computational tasks to coupling coefficient matrices in the quantum evolution space. When the quantum evolution system can be made large enough and its structure can be flexibly designed, it can be used to complete many algorithms and computational tasks, demonstrating performance far superior to traditional computers.
What are the differences between quantum chips and current integrated circuit chips?
Quantum chips perform quantum computing, while data integrated circuit chips perform data measurement; the two types of chips are different.
In data integrated circuit chips, high and low voltage frequencies represent 0 and 1 in binary algorithms, and logic operations are carried out using logic gates composed of transistors and MOSFETs.
Unlike integrated circuit chips, quantum chips require quantum computing, which uses two different quantum states, |0> and |1>, to represent 0 and 1 in quantum optimization algorithms. Quantum computing performed by quantum chips also requires corresponding quantum logic gates. Compared with digital circuit design, it can perform superposition state calculations and superposition state storage.
Here, we will mainly explain the calculation and storage of superposition states.
For a function f(x), if we want to input 100 values of x to get 100 results, how many times do we need to perform the calculation?
In classic calculations, the answer is very simple: calculate it 100 times, taking the x-value with each calculation.
However, in the calculations of quantum chips, only one calculation is needed.
Because the calculation module in the quantum chip is composed of qubits made up of quantum states, all x values are quantized. 100 x values can be accumulated into a mixed state. After being measured once in the quantum chip, a mixed state of 100 results can be obtained. Then, through certain precise measurements, the result with the corresponding x value can be obtained.
Then the corresponding superposition state storage is also easier to understand. We can mix 100 x values into one state for storage instead of using 100 memory locations.
Since quantum chips and integrated circuit chips perform completely different calculations, the differences become even greater when it comes to the specific components used. The advantage of quantum chips lies in their ability to accumulate quantum states from numerous initial values, thereby improving computational efficiency.
Which is stronger, photonic chips or quantum chips?
Photonic chips and quantum chips are two different concepts, neither superior to the other. Photonic chips utilize semiconductor light-emitting technology to generate continuous laser light, which powers other silicon photonic components; quantum chips integrate quantum circuits onto a silicon wafer, thereby enabling quantum information management functions.
Photonic chips can integrate the luminescence properties of indium phosphide and the optical router capabilities of silicon into a single hybrid chip. When current is applied to indium phosphide, the light waves entering the single-crystal silicon wafer are guided to generate continuous lasers. These lasers can drive other silicon photonic components.
These laser devices based on single-crystal silicon wafers enable the more widespread application of photonic chips in computers, as the use of large-scale silicon-based manufacturing technology can significantly reduce the cost of photonic chips. The development of quantum chips is attributed to the advancement of quantum computers. To achieve commercialization and industrial upgrading, quantum computers must adopt an integrated approach. Superconductor systems, semiconductor quantum dot systems, microstructured photonic systems, and even atomic and ionic systems are all striving for chip-based integration.
Looking at the development trend of chip technology, superconducting quantum chip systems are ahead of other physical systems in terms of technology; traditional semiconductor chip materials, namely quantum dot systems, are also the goal of our research. Since the traditional semiconductor chip industry is already very mature, if semiconductor quantum chips can improve the threshold of fault-tolerant quantum chip computing in terms of decoherence time and control precision, it is expected to integrate the existing achievements of the traditional semiconductor chip industry and greatly reduce project costs.
