26th Australian Institute of Physics Congress and the Australian and New Zealand Conference on Optics and Photonics

Session

AIP QST: Quantum algorithms, circuit design & complexity

QST

8 Dec 2026, 16:30

Belinda Hutchinson Building (The University of Sydney )

787. Constant Factor Analysis of Optimal Quantum Linear Solvers in Practice

Pedro Contino da Silva Costa (Macquarie University)

08/12/2026, 16:30

AIP | Quantum Science and Technology (QST)

Contributed Oral

Quantum linear system solvers are a central primitive in quantum algorithms, with applications ranging from differential equations to optimization, machine learning, and scientific computing. Several recent algorithms achieve the same optimal asymptotic query complexity, scaling as $O(\kappa \log(1/\epsilon))$, where $\kappa$ is the condition number and $\epsilon$ is the target precision....

422. Norm estimation for quantum linear systems solvers

Kaur Kristjuhan

08/12/2026, 16:45

AIP | Quantum Science and Technology (QST)

Contributed Oral

Quantum computers offer the prospect of exponential speedups for solving large linear systems. Quantum linear systems algorithms (QLSAs) prepare a quantum state encoding the solution of a linear system $Ax = b$, but many practical applications also require the norm of the solution. For example, when modelling fluid flow by discretising the governing equations, the solution vector encodes the...

459. Quantum Algorithm for solving differential equations using SLAC derivatives.

Rakshit Gharat (Macuqarie University)

08/12/2026, 17:00

AIP | Quantum Science and Technology (QST)

Contributed Oral

In numerical approaches to solving differential equations on a lattice, a representation of the derivative operator that correctly matches the continuum behaviour of momentum up to the band limit must be non-local. We present the construction of efficient linear-combination-of-unitaries ($\mathrm{LCU}$)-based block-encodings for the first-order derivative and Laplacian operators in the...

777. Tensor-Network-Inspired Variational Quantum Circuits for Quantum State Preparation

Bi Qi Chong (Nanyang Technological University)

08/12/2026, 17:15

AIP | Quantum Science and Technology (QST)

Contributed Oral

Preparing complex quantum states on noisy intermediate-scale quantum (NISQ) devices remains a fundamental challenge. Variational quantum algorithms (VQAs) provide a flexible framework for this task. However, their optimization often suffers from the barren plateau phenomenon, where gradients vanish exponentially as the system size increases. This has motivated two common classes of variational...

640. Every layer counts: Depth hierarchy for shallow quantum circuits

Xingjian Zhang (University of Technology Sydney)

08/12/2026, 17:30

AIP | Quantum Science and Technology (QST)

Contributed Oral

Circuit depth is a fundamental computational resource. In quantum computing, it serves as a direct proxy for the computational execution time before noise and decoherence dominate. A central question in (quantum) computation is whether increasing circuit depth strictly unlocks greater computational power. While crucial for designing scalable architectures, proving such a hierarchy...