trinity college dublin

In a very high magnetic field a 'massless' electron can acquire a mass

An international team of researchers have for the first time, discovered that in a very high magnetic field an electron with no mass can acquire a mass. 

Understanding why elementary particles e.g. electrons, photons, neutrinos have a mass is a fundamental question in Physics and an area of intense debate. This discovery by Prof Stefano Sanvito, Trinity College Dublin and collaborators in Shanghai was published in the prestigious journal Nature Communications this month.

While the applications of this discovery remain to be seen, this represents a significant breakthrough in fundamental physics. It could inspire work in high-energy physics, such as the collision experiments carried out in particle accelerators like CERN. This is the third joint publication between the group in Trinity and Prof. Faxian Xiu at Fudan University in Shanghai, who approached Prof Sanvito to provide theory support for their experimental activity based on his previous publications and international reputation in the field of theoretical physics.

Prof Stefano Sanvito, Principal Investigator at the Science Foundation Ireland funded AMBER (Advanced Materials and BioEngineering Research) centre based at Trinity and the CRANN Institute and Professor in Trinity’s School of Physics said, “This is a very exciting breakthrough because until now, nobody has ever discovered an object whose mass can be switched on or off by applying an external stimulus. Every physical object has a mass, which is a measure of the object’s resistance to a change in its direction or speed, once a force is applied. While we can easily push a light-mass shopping trolley, we cannot move a heavy-mass 6-wheel lorry by simply pushing. However, there are some examples in Nature of objects not having a mass. These include photons, the elementary particles discovered by Einstein responsible for carrying light, and neutrinos, produced in the sun as a result of thermonuclear reactions. We have demonstrated for the first time one way in which mass can be generated in a material. In principle the external stimulus that enabled this, the magnetic field, could be replaced with some other stimulus and perhaps applied long-term in the development of more sophisticated sensors or actuators. It is impossible to say what this could mean, but like any fundamental discovery in physics, the importance is in its discovery.”

He continued, “It has been very satisfying to continue to work with Prof Xiu in Shanghai. While his group are experts in growing and characterizing materials such as ZrTe5 which are very difficult to make, my group has the expertise in the theoretical interpretation. The measurements were carried out in Fudan and at the Wuhan National High Magnetic Field Center in China, while the Dublin team provided the theoretical explanation for the finding. This has been a very fruitful collaboration and we have a number of other publications in progress”.

The team studied what happened to the current passing through the exotic material zirconium pentatelluride (ZrTe5) when exposed to a very high magnetic field. Measuring a current in a high magnetic field is a standard way of characterising the material’s electronic structure. In the absence of a magnetic field the current flows easily through ZrTe5. This is because in ZrTe5 the electrons responsible for the current have no mass. However, when a magnetic field of 60 Tesla is applied (a million times more intense than the earth’s magnetic field) the current is drastically reduced and the electrons acquire a mass. An intense magnetic field in ZrTe5 transforms slim and fast electrons into fat and slow ones.

Nature communication (Open Article)

Zeeman splitting and dynamical mass generation in Dirac semimetal ZrTe5
Yanwen Liu, Xiang Yuan, Cheng Zhang, Zhao Jin, Awadhesh Narayan, Chen Luo, Zhigang Chen, Lei Yang, Jin Zou, Xing Wu, Stefano Sanvito, Zhengcai Xia, Liang Li, Zhong Wang & Faxian Xiu
Nature Communications 7, Article number: 12516 (2016)

AMBER (Advanced Materials and BioEngineering Research)

Nanotechnology World Association
Physicists Just Discovered a New Form of Light
A new form of light, one where the angular momentum of each photon takes only half of the value of Planck’s constant, has just been uncovered.

It’s easy to take light for granted and assume that we know everything there is to know about it—after all, it’s everywhere. But as it turns out, we might have only scratched the surface.

Today, physicists announced that they have discovered a new form of light. It’s completely different from our existing rules regarding light and angular momentum, showing that light can take on new and unexpected forms, and these could fundamentally change our current understanding of electromagnetic radiation.

(excerpt - click the link for the complete article)

  • Me:*in a pub with an Irish friend of mine*
  • Irish Friend:Fancy another pint?
  • Me:Always!
  • Irish Friend:Ha ha, grand. You're gas.
  • Me:I'm what?
  • Waiter:*drops a glass*
  • Irish Friend:Oi, your man there is such a feckin' eejit.
  • Me:
  • Irish Friend:
  • Me:
  • Irish Friend:
  • Me:
  • Irish Friend:
  • Me:I have a question, and I cannot overemphasize how seriously I'm asking.
  • Irish Friend:What's that?
  • Me:Do you think we're speaking the same language right now?

So my college are currently doing this ‘Jailbreak’ thing where you have like 48 hours to get as far away from college as you can with no money and you’re supposed to get airlines and stuff to sponsor you and raise money for charities

and there are people in like Austria and stuff, which is cool

but there’s this one team

who went to Dublin airport


talked to him


The University Times: With Thoughtful Responses, Hozier Answers Questions on Music and Making a Difference

Hozier addressed social issues, being young and Irish, and dropping out of Trinity.


Sam McAllister for The University Times

When Hozier entered the Edmund Burke theatre to a crowd of shouting and clapping students up on their feet, looking slightly bewildered and fumbling with the mic attached to his clothes, he set the tone for what was to be a humble and endearing question and answer session with the audience. When the President of the Phil, Ludivine Rebet, posed the first question of the evening, asking him about his recent touring, he described how, after two years of shows on both sides of the Atlantic that were steadily increasing in size, he was now, finally, back home. Turning to the audience, he professed, laughing: “I don’t know what to do with myself!”

This was, however, exactly what the audience wanted to know – what he was doing with himself. While most guests that visit Trinity’s societies start with a speech, this visit consisted entirely of questions and answers, and the audience, which didn’t quite fill up the 400-seat theatre but was made up of an eager audience including the Provost, Patrick Prendergast, was definitely curious.

Hozier was asked about the progress of his next album, which he admitted he had given some thought to but still has “no definite shape” due the hectic nature of touring and the limited time he has on the road to explore ideas. He was also asked about his creative process and how he found his artistic voice, and he explained that much of his musical education came from folk and blues music: “With a lot of this music you’re listening to the surrounding circumstances, the social and economic circumstances, and that’s conveyed through one voice, with this human in the centre of it.” He continued: “I don’t know where I found my voice. I started at 15 and I wasn’t happy until I was 23. It took me a long time to figure out what space I wanted my music to exist in – hard work and a lot of failure.”

On his relationship with Ireland as a nation, and on whether or not that relationship had changed with the successes his music had brought, he commented that “the relationship has changed a little bit in the last few years, because people now recognise me, and no where else more than Ireland. Being an Irish citizen is different now – not in a negative way, but I’m still figuring it out”.

He continued: “I still love Ireland very much and I’ve been proud of a lot of the progress made. I still love this place. It’s still home to me.”

Almost every one of Hozier’s sentences was ended with a laugh, and this laugh was always matched by the audience. He greeted lighthearted questions with large, booming laughs, and, when speaking on a serious topic or making a serious point, he added a smaller laugh, or trailed off, indicating that he didn’t want to take himself too seriously.

These serious topics came up often. After all, his talk was part of the Activist Festival, a two-day festival hosted by Trinity College Dublin Students’ Union (TCDSU) that aims to empower young activists to enact social change in the areas including housing, LGBT rights and gender equality. The festival finished today, with Hozier’s talk, organised by the Phil.

TCDSU President Lynn Ruane asked Hozier if he would “merge social activism of music with grassroots movements”, using his political capital to have “tens of thousands” of people show up. While Hozier first responded sheepishly, first stating “you flatter me” and that he doubted he could draw that many people, he spoke of his optimism about the future of music’s engagement with social issues, pointing to modern hip-hop artists like Kendrick Lamar and Run the Jewels. When asked if he would sign the open letter calling on College to divest from its €6 million assets in fossil fuels he stated that it was not an issue he was aware of, but that he would be interested in reading it.

It was when talking about the social issues he’s passionate about that Hozier came across as most confident and inspiring. Indeed, Hozier’s first single, Take Me to Church, was accompanied by a powerful video that addresses discrimination against homosexuals in Russia. The video now has over 317 million views.

Just yesterday, Hozier performed in at Áras an Úachtaráin following a speech by the President of Ireland, Michael D Higgins, as part of the UN’s HeForShe Campaign, which calls on men to become more active in combating gender inequality and gender-based violence. President Higgins then made reference to Cherry Wine, Hozier’s latest single whose video deals with the theme of domestic violence. The song’s proceeds from iTunes are being distributed to international domestic abuse charities. Addressing this today, he commented on how the campaign is “about men recognising their role in the issue about violence about women”.

The room erupted in cheers when, after being asked if he was a feminist, he frankly stated “of course, yeah”. “I think being a feminist is a simple, fundamental thing … It’s not a big deal. It’s a case of saying ‘yes, I believe in an equal society’.”

Hozier endorsed Bernie Sanders, explained the influence that Jame’s Joyce’s A Portrait of the Artist as a Young Man had on his album, admitted that his first shows in New York were his favourite shows in the US and was left blushing after an audience member referred to his as both “a musical genius and a poet”. “I could never describe myself as a poet because I have too much respect for what poets do”, he explained, “music comes a bit more instinctively … but lyrics are what grab people.”

Prof Anthony Staines of DCU, who is running for the TCD Seanad panel, stated his belief that more the festival should have focused on youth issues, stating frankly “the short message is that your generation is screwed”. In response, Hozier was honest about the difficulties of addressing such issues: “I don’t know where to begin. If you could somehow get through the message that this is our country, this is our nation and we are the rulers of tomorrow’” adding, with characteristic frankness and honesty, “Enda Kenny was asking people to come home for work, but there is no fucking work here”.

Few speakers who come to Trinity have in-depth knowledge of the College, but Hozier’s past in here earned him a warm reception from the crowd. He outlined frankly why he dropped out of music in his first year: “I was underprepared for things like composition and general theory, so I knew it was going to be a struggle. I knew I didn’t want to be an academic. I knew I wanted to write music, to contribute to the Irish cannon. I knew the skills I needed wouldn’t get in this formal education.” He added: “I love this place. I’m still incredibly fond of this College and everything I got here.”

Judging from the hoards of people who followed him across Front Square to seek a selfie, the college feels the same way.