Variational Quantum Algorithms: A Comprehensive Review

Quantum computing is a new frontier in the world of computers. It’s like having a superpower for solving complex problems that classical computers can’t handle as quickly or efficiently. Imagine you have a to-do list with millions of items, and you need to check each one to see if it’s important. A classical computer would take ages to do this, but a quantum computer could zip through the list in no time!
This new computational framework is revolutionizing many fields, from breaking encryption codes to simulating quantum systems. Quantum singular value transformation (QSVT) has led to a unified framework of most known quantum algorithms, including amplitude amplification, quantum walks, phase estimation, and Hamiltonian simulations. These tools can help develop new quantum algorithms for estimating entropies, fidelity, ground state preparation, and ground energy estimation.
Entropies are like the mysterious powers of the universe. They measure how much information is hidden in a system. By estimating these powers using quantum computers, scientists can uncover secrets that were previously invisible to classical tools. Fidelity, on the other hand, measures how well a quantum state resembles its original form. Estimating fidelity helps ensure that quantum systems are in good shape and don’t degrade over time.
Ground state preparation is like planting a garden. You need to prepare the right soil, add the right seeds, and nurture them until they grow into beautiful plants. In quantum computing, ground state preparation helps create the perfect environment for a quantum system to exist in its purest form. Ground energy estimation is like measuring the total amount of energy in a garden. By estimating this quantity using quantum computers, scientists can gain insights into the behavior of quantum systems that were previously unknown.
These new quantum algorithms have the potential to revolutionize many fields and solve problems that were previously unsolvable. Quantum computing is like having a superpower for solving complex problems, and it’s an exciting time for scientists as they continue to explore its full potential!