A team of researchers from the California Institute of Technology (Caltech), Microsoft Research AI4Science Lab, and Tencent Quantum Lab has presented a groundbreaking algorithm that aims to overcome the challenge of achieving chemical accuracy with shallow quantum circuits. Their algorithm, known as CHEM, is based on a Clifford-based Hamiltonian engineering approach and offers a promising avenue for practical quantum computational chemistry on near-term quantum devices.
The main challenge in quantum computational chemistry, especially for near-term quantum devices, lies in finding a balance between circuit depth and accuracy. The researchers addressed this trade-off by using a combination of the variational quantum eigensolver and a hardware-efficient ansatz. The result was a method that designs Clifford-based Hamiltonian transformations, which have several key advantages.
Firstly, the method ensures that a set of initial circuit parameters corresponding to the Hartree-Fock energy can be generated. This is crucial for achieving accurate results in quantum chemical calculations. Secondly, it effectively maximizes the initial energy gradient with respect to circuit parameters, further enhancing accuracy. Importantly, the approach imposes negligible overhead for classical processing and does not require additional quantum resources, making it highly efficient and practical.
One of the notable achievements of this approach was demonstrated using a quantum hardware emulator. The researchers were able to achieve chemical accuracy for systems as large as 12 qubits with fewer than 30 two-qubit gates. This is a significant advancement in the field of quantum computational chemistry and brings us a step closer to achieving practical applications on near-term quantum devices.
The findings of this research paper open up new possibilities for quantum computing, particularly in the domain of chemistry. As more advancements are made in quantum hardware and algorithms, the race towards quantum advantage continues. Although quantum computers have yet to surpass conventional computers, breakthroughs like the CHEM algorithm bring us closer to the day when quantum computing will truly revolutionize various industries.
The source of the article is from the blog motopaddock.nl