Didn’t find the answer you were looking for?
When should variational algorithms like VQE be used instead of traditional quantum algorithms?
Asked on Oct 13, 2025
Answer
Variational algorithms like the Variational Quantum Eigensolver (VQE) are particularly useful when dealing with problems that are too complex for traditional quantum algorithms, especially in the context of current noisy intermediate-scale quantum (NISQ) devices. VQE is often applied in quantum chemistry and materials science to find the ground state energy of a molecule, leveraging a hybrid quantum-classical approach to optimize parameters of a quantum circuit.
Example Concept: The VQE algorithm uses a parameterized quantum circuit to prepare quantum states and a classical optimizer to minimize the expected value of the Hamiltonian. This hybrid approach is beneficial for NISQ devices because it reduces the depth of quantum circuits, making them less susceptible to noise and decoherence compared to traditional quantum algorithms that require deep circuits.
Additional Comment:
- Variational algorithms like VQE are advantageous for problems where the solution space is vast and not easily navigable by traditional quantum algorithms.
- They are especially suitable for NISQ devices due to their resilience to noise and lower circuit depth requirements.
- VQE can be implemented using frameworks like Qiskit, which provides tools for constructing parameterized circuits and integrating classical optimization routines.
Recommended Links:
