Publications related to Optical rotatory dispersion

Nonlinear optical diode effect in a magnetic Weyl semimetal

Philip Johannes Walter Moll, Chunyu Guo, Hao Yang

Diode effects are of great interest for both fundamental physics and modern technologies. Electrical diode effects (nonreciprocal transport) have been observed in Weyl systems. Optical diode effects arising from the Weyl fermions have been theoretically co ...

Nature Portfolio2024

The fundamental relation between electrohelicity and molecular optical activity

Anne-Clémence Corminboeuf, Marc Hamilton Folkmann Garner

Electrohelicity arises in molecules such as allene and spiropentadiene when their symmetry is reduced and helical frontier molecular orbitals (MOs) appear. Such molecules are optically active and electrohelicity has been suggested as a possible design prin ...

ROYAL SOC CHEMISTRY2023

Magneto-optical study of metamagnetic transitions in the antiferromagnetic phase of alpha-RuCl3

Zhe Wang

alpha-RuCl3 is a promising candidate material to realize the so far elusive quantum spin liquid ground state. However, at low temperatures, the coexistence of different exchange interactions couple the effective pseudospins into an antiferromagnetically zi ...

NATURE PORTFOLIO2022

Chiral control of spin-crossover dynamics in Fe (II) complexes

Majed Chergui, Malte Oppermann, Jérôme Lacour

Iron-based spin-crossover complexes hold tremendous promise as multifunctional switches in molecular devices. However, real-world technological applications require the excited high-spin state to be kinetically stable-a feature that has been achieved only ...

NATURE PORTFOLIO2022

Hard X-ray helical dichroism of disordered molecular media

Majed Chergui, Giulia Fulvia Mancini, Malte Oppermann, Camila Bacellar Cases Da Silveira, Dominik Kinschel, Oliviero Cannelli, Christian David, Jérôme Lacour

Chirality is a structural property of molecules lacking mirror symmetry that has strong implications in diverse fields, ranging from life sciences to materials science. Chirality-sensitive spectroscopic methods, such as circular dichroism, exhibit weak sig ...

Nature Publishing Group2022

Polarization-sensitive optics diffraction tomography

Demetri Psaltis, Joowon Lim, Elizabeth Elena Antoine, Amirhossein Saba Shirvan, Ahmed Ayoub

Polarization of light has been widely used as a contrast mechanism in two-dimensional (2D) microscopy and also in some three-dimensional (3D) imaging modalities. In this paper, we report the 3D tomographic reconstruction of the refractive index (RI) tensor ...

2021

Complementary Metasurfaces for Guiding Electromagnetic Wave

Mohammad Sajjad Mirmoosa

Metasurfaces can be employed for designing waveguides that confine the electromagnetic energy while they are open structures. In this communication, we introduce a new type of such waveguides, formed by two penetrable metasurfaces having complementary isot ...

2021

Helical electronic transitions of spiroconjugated molecules

Anne-Clémence Corminboeuf, Marc Hamilton Folkmann Garner

The two pi-systems of allene can combine into helical molecular orbitals (MOs), yet the helicity is lost in the pi-pi* transitions due to excited state mixing. In spiroconjugated molecules the relative orientation of the two pi-systems is different and con ...

Royal Society of Chemistry2021

Discrete metal nanoparticles with plasmonic chirality

Jijun He

From a geometrical perspective, a chiral object does not have mirror planes or inversion symmetry. It exhibits the same physical properties as its mirror image (enantiomer), except for the chiroptical activity, which is often the opposite. Recent advanceme ...

Royal Society of Chemistry2021

Twisted Bilayer Graphene Quantum Dots for Chiral Nanophotonics

Twisted bilayer graphene (TBG) is a two-dimensional chiral material whose optical activity is remarkably strong for its atomic thickness. While the chiral optical properties of TBG are currently well understood, the optical activity of quantum dots (QDs) m ...

2020

Absolute Structure from Scanning Electron Microscopy

Philip Johannes Walter Moll

The absence of centrosymmetry in chiral and polar crystal structures is the reason for many technical relevant physical properties like optical birefringence or ferroelectricity. Other chirality related properties that are actually intensively investigated ...

Nature Research2020

Correlation between Optical Activity and the Helical Molecular Orbitals of Allene and Cumulenes

Anne-Clémence Corminboeuf, Marc Hamilton Folkmann Garner

Helical frontier molecular orbitals (MOs) appear in disubstituted allenes and even-n cumulenes. Chiral molecules are optically active, but while these molecules are single-handed chiral, p-orbitals of both helicities are present. Here we computationally ex ...

AMER CHEMICAL SOC2020

Accessible Superchiral Near-Fields Driven by Tailored Electric and Magnetic Resonances in All-Dielectric Nanostructures

Hatice Altug, Andreas Tittl, Yasaman Jahani, Kosmas Tsakmakidis, Ershad Mohammadi

Detection and differentiation of enantiomers in small quantities are crucially important in many scientific fields, including biology, chemistry, and pharmacy. Chiral molecules manifest their handedness in their interaction with the chiral state of light ( ...

AMER CHEMICAL SOC2019

Terahertz-optical properties of a bismuth ferrite single crystal

Henrik Moodysson Rønnow, Jean-Philippe Ansermet, Marcin Bialek

Transmission through a (100)-oriented single crystal of bismuth ferrite (BiFeO3) was studied at frequencies of 0.485-0.765 THz with a continuous-wave source and in the temperature range of 30-350 K as a function of polarization angle. The fine splitting of ...

2019

Enhanced Circular Dichroism and Chiral Sensing with Bound States in the Continuum

Hatice Altug, Andreas Tittl, Yasaman Jahani

We reveal that optical chirality at the nanoscale can be boosted dramatically by bound states in the continuum (BIC). We predict the enhancement of chiroptical signals from nanostructures supporting quasi-BICs in mid-IR with a record-high efficiency. (C) 2 ...

IEEE2019

Broad-Band Ultraviolet CD Spectroscopy of Ultrafast Peptide Backbone Conformational Dynamics

Majed Chergui, Malte Oppermann, Benjamin Bauer

The far-UV spectral window widely used for the conformational analysis of biomolecules is not easily covered with broad-band lasers. This has made it difficult to use circular dichroism (CD) spectroscopy to directly follow fast structure changes. By combin ...

AMER CHEMICAL SOC2019

Nanophotonic Platforms for Enhanced Chiral Sensing

Hatice Altug, Kosmas Tsakmakidis, Ershad Mohammadi

Chirality plays an essential role in life, providing unique functionalities to a wide range of biomolecules, chemicals, and drugs, which makes chiral sensing and analysis critically important. The wider application of chiral sensing continues to be constra ...

2018

Observation of two independent skyrmion phases in a chiral magnetic material

Helmuth Berger

Magnetic materials can host skyrmions, which are topologically non-trivial spin textures. In chiral magnets with cubic lattice symmetry, all previously observed skyrmion phases require thermal fluctuations to become thermodynamically stable in bulk materia ...

2018

Brillouin dynamic gratings in optical fibres for distributed sensing and advanced optical signal processing

Andrey Denisov

This thesis presents results of a research on applications of Brillouin dynamic gratings - distributed reflectors that can be dynamically created in an optical fibre by two optical waves. A basic theory of stimulated Brillouin scattering (SBS) is introduce ...

EPFL2015

Innovative optical lactate biosensing through the design of nanostructured materials

Oswaldo Javier Pérez Anguiano

The scope of this thesis is the synthesis of nanostructured materials, their functionalization and use for optical lactate biosensing applications. Rapid detection of L-lactate is important in many applications in the clinical sector, in the food industry, ...

EPFL2015