Nav: Home

A distinct spin on atomic transport

November 08, 2019

One of the more unexpected things that can be done with charge-neutral atoms is to use them to emulate the fundamental behaviour of electrons. In the past few years, the group of Tilman Esslinger at the Institute of Quantum Electronics in the Department of Physics of ETH Zurich has pioneered a platform in which atoms cooled to temperatures close to absolute zero are transported through one- and two-dimensional structures, driven by a potential difference. In this way defining phenomena occuring in mesoscopic electronic systems can be studied in great detail, not least quantized conductance. In a pair of papers published today in Physical Review Letters and Physical Review A, postdoc Laura Corman, former PhD student Martin Lebrat and colleagues in the Esslinger group report that they have mastered in their transport experiments control over another quantum property of the atoms --- their spin.

The team added to the transport channel a tightly focussed light beam, which induces local interactions that are equivalent to exposing the atoms to a strong magnetic field. As a consequence, the degeneracy of the spin states is lifted, which in turn serves as the basis for an efficient spin filter: atoms of one spin orientation are repelled, whereas those of another orientation are free to pass (see the figure). Importantly, even though the application of an additional light field leads to the loss of atoms, these dissipative processes do not destroy the quantization of conductance. The ETH researchers replicate this experimental finding in numerical simulation and substantiate its validity through an extension of the Landauer--Büttiker model, the key formalism for quantum transport.

The efficiency of the atomic spin filter demonstrated by the Esslinger group matches that of the best equivalent elements for electronic systems. This, together with the extraordinary 'cleanness' and controllability of the cold-atom platform, opens up exciting new perspectives for exploring the dynamics of quantum transport. In particular, as the interaction between the atoms can be tuned, the platform provides access to spin transport of strongly correlated quantum systems. This regime is difficult to study otherwise, but is of considerable fundamental and practical interest, not least for applications in spintronic devices and to explore fundamental phases of matter.

ETH Zurich Department of Physics

Related Physics Articles:

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.
Physics at the edge
In 2005, condensed matter physicists Charles Kane and Eugene Mele considered the fate of graphene at low temperatures.
Using physics to print living tissue
3D printers can be used to make a variety of useful objects by building up a shape, layer by layer.
More Physics News and Physics Current Events

Trending Science News

Current Coronavirus (COVID-19) News

Top Science Podcasts

We have hand picked the top science podcasts of 2020.
Now Playing: TED Radio Hour

Listen Again: Meditations on Loneliness
Original broadcast date: April 24, 2020. We're a social species now living in isolation. But loneliness was a problem well before this era of social distancing. This hour, TED speakers explore how we can live and make peace with loneliness. Guests on the show include author and illustrator Jonny Sun, psychologist Susan Pinker, architect Grace Kim, and writer Suleika Jaouad.
Now Playing: Science for the People

#565 The Great Wide Indoors
We're all spending a bit more time indoors this summer than we probably figured. But did you ever stop to think about why the places we live and work as designed the way they are? And how they could be designed better? We're talking with Emily Anthes about her new book "The Great Indoors: The Surprising Science of how Buildings Shape our Behavior, Health and Happiness".
Now Playing: Radiolab

The Third. A TED Talk.
Jad gives a TED talk about his life as a journalist and how Radiolab has evolved over the years. Here's how TED described it:How do you end a story? Host of Radiolab Jad Abumrad tells how his search for an answer led him home to the mountains of Tennessee, where he met an unexpected teacher: Dolly Parton.Jad Nicholas Abumrad is a Lebanese-American radio host, composer and producer. He is the founder of the syndicated public radio program Radiolab, which is broadcast on over 600 radio stations nationwide and is downloaded more than 120 million times a year as a podcast. He also created More Perfect, a podcast that tells the stories behind the Supreme Court's most famous decisions. And most recently, Dolly Parton's America, a nine-episode podcast exploring the life and times of the iconic country music star. Abumrad has received three Peabody Awards and was named a MacArthur Fellow in 2011.