| Energy is information. Lengthening the time during which a system is capable of retaining energy before losing it to the local environment is a key goal for the development of quantum information. This interval is called the “coherence time”. Several studies have been performed with the aim of retarding decoherence. | |
| A study conducted by researchers at the University of Campinas’s Gleb Wataghin Institute of Physics (IFGW-UNICAMP) in São Paulo State, Brazil, in partnership with colleagues at the University of Michigan’s Physics Department in Ann Arbor, USA, and Sungkyunkwan University’s Advanced Institute of Nanotechnology (SAINT SKKU) in Seoul, South Korea, set out to understand the decoherence process on the femtosecond (10-15 s) timescale. | |
| An article describing the results was published in Physical Review Letters (“Non-Markovian Exciton-Phonon Interactions in Core-Shell Colloidal Quantum Dots at Femtosecond Timescales”). |
| In the study, interactions between excitons (excited electrons) and phonons (quantum units of vibrational energy in a crystal lattice) were observed on the femtosecond timescale. A femtosecond is one quadrillionth of a second. | |
| The use of a revolutionary ultrafast spectroscopy technique with high temporal and spectral resolution was fundamental to the success of the study, which was supported by FAPESP via a Young Investigator Grant awarded to Lázaro Aurélio Padilha Junior and a project conducted in partnership with the University of Michigan under the aegis of the São Paulo Research Foundation – FAPESP program São Paulo Researchers in International Collaboration (SPRINT). | |
| Padilha was one of the principal investigators for the project, and Diogo Burigo Almeida, then a postdoctoral fellow at Michigan, was one of the main authors. The experiment was performed with semiconducting nanocrystals dispersed in a colloidal solution at cryogenic temperatures. | |
| “We found that when the material is excited [by light], the light it emits changes color in under 200 femtoseconds. This is due to interaction between excitons and phonons. The excitons transfer part of the energy they receive to the crystal lattice. This causes a change of frequency and hence a change of emission color,” Padilha told. |
Image Credit: Image courtesy of the researchers
News This Week
Omicron subvariant BA.2 replicates faster in brain cells than other strains, study finds
Omicron subvariant BA.2 – which was dominant worldwide early this year, including in Hong Kong – replicates more swiftly than other strains and causes faster programmed cell death in human brains, a new study has found. [...]
Seeding the oceans with iron-rich fertilizer nanoparticles to store excess carbon dioxide
The urgent need to remove excess carbon dioxide from Earth’s environment could include enlisting some of our planet’s smallest inhabitants, according to an international research team led by Michael Hochella of the Department of [...]
Temporary graphene ‘tattoos’ that measure blood pressure
Blood pressure is a key vital sign that provides insight into our cardiovascular health. But blood pressure is typically measured only a few times per year by a clinician—and these measurements might not always [...]
Next Covid-19 Strain May be More Dangerous, Lab Study Shows
A South African laboratory study using Covid-19 samples from an immunosupressed individual over six months showed that the virus evolved to become more pathogenic, indicating that a new variant could cause worse illness than [...]
The Fast-Spreading New COVID-19 Subvariant XBB Is Part of a ‘New Class’ of Omicron
For the past several months, Omicron subvariants BA.4 and BA.5 have dominated COVID-19 cases in the U.S. But now, there’s a class of new COVID subvariants on the rise and one in particular is getting plenty of [...]
Overcoming challenges in the delivery of nucleic acid therapeutics
Nucleic acid therapies involving DNA or RNA have significant potential to treat genetic disorders, infectious diseases, and cancer; however, research suggests that less than 1% of injected nucleic acid doses reach target cells in [...]
FDA approves $3.5 million treatment for hemophilia, now the most expensive drug in the world
The US Food and Drug Administration on Tuesday approved Hemgenix, a new drug to treat hemophilia. Manufacturer CSL Behring set the price at $3.5 million per treatment, making it the most expensive drug [...]
Wireless smart bandage promotes faster closure of wounds, enhances skin recovery
Some wounds just won’t heal. Infections, diseases like diabetes, and suppressed immune systems often stack up to slow healing. Chronic wounds can last months and lead to anxiety and depression. In the worst cases, [...]
Using Nanofibers to Guide the Development of Novel Biomaterials
Over the years, researchers have tried hard to comprehend topographic signals that promote cell mechanical sensitive responses. The extracellular matrix (ECM) provides a complex cellular microenvironment that controls cellular behavior. Nevertheless, only a few [...]
Measles now an imminent global threat due to pandemic, say WHO and CDC
There is now an imminent threat of measles spreading in various regions globally, as COVID-19 led to a steady decline in vaccination coverage and weakened surveillance of the disease, the World Health Organization (WHO) [...]
Covid-19: Brain scans show new evidence of what could be causing long Covid
In a recent study, it was shown that people with long Covid have had physical changes to their brains several months after experiencing the initial infection. The study included MRIs of patients who continued [...]
Western University is building Canada’s secret weapon against the next pandemic
Western University in London, Ont., is building a unique research lab to study humanity's greatest viral threats — a secret weapon, if you will, one that it's expected would put Canada and the world in a better position if [...]
Cancer patients test world’s first ‘computer-designed’ antibodies, made in Israel
Cancer patients are testing a medicine made of antibodies that were designed from scratch on a computer in Israel and whose inventor has “programmed” them to “decide” whether cells surrounding tumors are bad or good. [...]
Corrosion-Resistant Superhydrophobic Graphene-Based Coatings on Copper Substrate
In an article published in the journal Scientific Reports, researchers presented the potentiostatic deposition used to electrodeposit nickel (Ni) and nickel-graphene (Ni-G) films on copper substrates. Myristic acid (MA) was employed to alter the plane of the [...]
A chip to replace animal testing
New drugs made from nanoparticles that can easily penetrate any interface within our bodies are a great hope in medicine. For such hopefuls to reach the market, their safety must be ensured. In this [...]
Researchers develop new, heat-efficient nanoparticles for treating cancer
Oregon State University scientists have invented a way to make magnetic nanoparticles that get hotter than any previous nanoparticle, improving their cancer fighting ability. Faculty from the OSU College of Pharmacy spearheaded a collaboration [...]
