A team led by researchers from MIT has developed a framework to reduce noise in the quantum circuit to make it more Robust, thus improving the efficiency and accuracy of quantum computers. The research will be presented at the IEEE International Symposium on High-Performance Computer Architecture.
Quantum computing is experiencing an unprecedented level of development. Quantum computers perform computing operations using “quantum circuits”, which are a series of operations called quantum gates. The quantum gates are mapped to individual quantum bits and changing the quantum states of specific qubits is required to perform the calculations. But one problem that has puzzled the scientists and researchers is a way to mitigate noise that hampers its accuracy and plagues quantum machines. This noise is caused due to interference from the environment, weak control signals and unwanted interactions between quantum bits also known as qubits, which are considered as the building blocks of quantum computing.
To mitigate the problem of noise, the team has created a framework called the QuantumNAS (noise adaptive search) that identifies the most robust quantum circuit and generates a mapping pattern specific to every qubit of a targeted quantum device for every particular task. The framework is capable of improving the accuracy of the machine learning and quantum chemistry task and requires lower resources as it is much less computationally intensive than other available search methods.
“The key idea here is that, without this technique, we have to sample each individual quantum circuit architecture and mapping scenario in the design space, train them, evaluate them, and if it is not good, we have to throw it away and start over. But using this method, we can obtain many different circuits and mapping strategies at once with no need for many times of training,” said Song Han, who is a senior author of the paper and an associate professor in the Department of Electrical Engineering and Computer Science at MIT.
The main problem encountered during the research was the possibility of many design choices. “We know that different qubits have different properties and gate error rates. Since we’re only using a subset of the qubits, why don’t we use the most reliable ones? We can do this through co-search of the architecture and qubit mapping,” said one of the lead author Hanrui Wang, MIT’s EECS graduate students.
You can read more about this research here.