Low Order Non-Linear Spectroscopy and its Implications for the Study of Chiral Molecules – Joshua Vogwell (Attosecond Optical Science)
Chirality is a geometric property possessed by objects which are non-superimposable with their mirror image. Oppositely handed versions of a chiral molecule, or enantiomers, have identical physical properties except when they interact with other chiral objects. Most biological matter is chiral, and so chiral recognition is vital, especially in biological and pharmacological contexts. Traditional chiro-optical methods, such as optical rotation, are limited in their efficiency since they rely on weak linear effects which arise beyond the electric dipole approximation.
Much recent work has been done to develop and investigate methods for distinguishing opposite enantiomers using physics which arises purely within the electric dipole approximation. For example, we have recently developed [1] an ultrafast and all-optical approach for chiral discrimination based on chiral sum-frequency generation (SFG)[2], and demonstrated how it can drive strongly enantio-sensitive optical signals in the chiral molecule propylene oxide.
We present our findings both on simulations of chiral SFG in propylene oxide and on simulations of the ultrafast electronic response of the conformers of carvone [3], showing that chiral SFG is a viable probe of molecular chirality, how this technique is impacted by conformational differences within a sample, and that an enantio-sensitive response survives the coherent addition of contributions from multiple conformers.
Generating Resource States for Linear Optical Fusion-Based Quantum Computing – Sara Bartolucci (Quantum Science and Technology)
Fusion-Based Quantum Computation (FBQC) is a framework for fault-tolerant quantum computing based on the use of two primitives: multi-qubit entangling measurements, known as “fusions”, and small, constant-size entangled states, known as “resource states”. In the linear optical implementation of FBQC, resource states are themselves generated by applying fusions between smaller “seed states”. This talk will provide an overview of linear optical FBQC, with a particular focus on the process and challenges of generating resource states in this platform.
Quantum error cancellation for photonic systems – undoing photon losses – Adam Taylor (Quantum Science and Technology)
When measuring expectation values in photonic platforms, photon losses are often the dominant source of error. In this talk, I will introduce a quantum error mitigation protocol that can undo the effects of photon losses in expectation values. The key theoretical insight is a derivation of the (non-physical) inverse photon loss map from which we construct two mitigation schemes; a heralded approach that can achieve arbitrarily small bias at the cost of increasing sampling overhead, and an unbiased approach based around Monte-Carlo sampling different initial condition. To validate the proposed schemes, we classically simulated several paradigmatic examples.