Investigating optical activity under an external magnetic field

November 06, 2020

Optical activity in chiral molecules has become a hot topic in physics and optics, representing the ability to manipulate the polarized state of light. Understanding how molecules rotate the plane of plane-polarized light has widespread applications, from analytic chemistry to biology and medicine--where it can, for example, be used to detect the amount of sugar in a substance. A new study published in EPJ B by Chengping Yin of the Guangdong Provincial Key Laboratory of Quantum Engineering and Quantum Materials, South China, aims to derive an analytical model of optical activity in black phosphorous under an external magnetic field.

Yin and his fellow authors experimented with black phosphorous?--?a thermodynamically stable form of phosphorus at room temperature and pressure, first synthesized in 1914?--?in a single, closely packed layer of atoms or a monolayer. The researchers discovered that in addition to expected strong optical activity, dichroism?--transmittance difference between left and right circularly polarized light--and circular birefringence, they could tune the phenomena created by altering the applied magnetic field.

The team reached their findings by deriving an analytical method to calculate the optical activity in a monolayer of black phosphorous under an external magnetic field. They were then able to obtain results showing how optical activity can be altered by changing the incident angle of the impinging light and by adjusting the magnitude of the applied magnetic field.

The results discussed in the paper show optical activity conforming to that previously observed in chiral metamaterials?--?material engineered to have a property that is not found in naturally occurring materials. In addition to this, they found the co-polarization transmittance increased in step with the angular frequency. The team explains the reason for this is that the conductivity of the monolayer black phosphorous decreases with increasing angular frequency, resulting in a weaker interaction with the incident light.

The researchers say that their findings could have applications in polarization optics, stereochemistry?--?the study of the relative spatial arrangement of atoms that form the structure of molecules and their manipulation?--?and molecular biology.

C. Liu, F. Wu, Q. Jiang, Y Chen, C. Yin (2020), Theory for optical activity in monolayer black phosphorus under external magnetic field, European Physical Journal B 93:197, DOI: 10.1140/epjb/e2020-10390-0


Related Physics Articles from Brightsurf:

Helium, a little atom for big physics
Helium is the simplest multi-body atom. Its energy levels can be calculated with extremely high precision only relying on a few fundamental physical constants and the quantum electrodynamics (QED) theory.

Hyperbolic metamaterials exhibit 2T physics
According to Igor Smolyaninov of the University of Maryland, ''One of the more unusual applications of metamaterials was a theoretical proposal to construct a physical system that would exhibit two-time physics behavior on small scales.''

Challenges and opportunities for women in physics
Women in the United States hold fewer than 25% of bachelor's degrees, 20% of doctoral degrees and 19% of faculty positions in physics.

Indeterminist physics for an open world
Classical physics is characterized by the equations describing the world.

Leptons help in tracking new physics
Electrons with 'colleagues' -- other leptons - are one of many products of collisions observed in the LHCb experiment at the Large Hadron Collider.

Has physics ever been deterministic?
Researchers from the Austrian Academy of Sciences, the University of Vienna and the University of Geneva, have proposed a new interpretation of classical physics without real numbers.

Twisted physics
A new study in the journal Nature shows that superconductivity in bilayer graphene can be turned on or off with a small voltage change, increasing its usefulness for electronic devices.

Physics vs. asthma
A research team from the MIPT Center for Molecular Mechanisms of Aging and Age-Related Diseases has collaborated with colleagues from the U.S., Canada, France, and Germany to determine the spatial structure of the CysLT1 receptor.

2D topological physics from shaking a 1D wire
Published in Physical Review X, this new study propose a realistic scheme to observe a 'cold-atomic quantum Hall effect.'

Helping physics teachers who don't know physics
A shortage of high school physics teachers has led to teachers with little-to-no training taking over physics classrooms, reports show.

Read More: Physics News and Physics Current Events is a participant in the Amazon Services LLC Associates Program, an affiliate advertising program designed to provide a means for sites to earn advertising fees by advertising and linking to