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Quantum electron ‘submarines’ help push atoms around
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TD We regard emails as ordinary conversations, and some of those we regard as personal and confidential. The FOI act is clearly laudable. But we also believe there is an argument for confidentiality. The trouble is, that is interpreted by some as being somehow sinister, when it clearly is not in the vast majority of cases. US law accepts that emails between colleagues when they’re working on a paper and around peer review should not be disclosable. That came about because of what was described as a potentially chilling effect on research if every single email exchange was released. Phil, did you delete any emails out of concern that they might be the subject of FOI requests? PJ I haven’t deleted any emails
Electron ‘submarines’ help push atoms around IMAGINE a machine that can assemble an object atom by atom. That may be a step closer with the demonstration of electrons moving like a “quantum submarine” inside a material. Manipulating atoms directly is a major goal of nanotechnology, but remains a long way off. The best that has been achieved so far is to push individual atoms around using a scanning tunnelling microscope (STM), a device which can obtain images at the atomic scale using electrons emitted from a stylus just one atom wide at its tip. Now Richard Palmer, Peter Sloan
“A silicon wafer could have numerous pits where that were the subject of FOI electrons can be injected, requests, but I have deleted emails manipulating many atoms” because I just have too many to cope with. I’m deleting 50 every day at the moment. It would be very difficult to guess what might –Jones became a marked man– be asked for in the future so I don’t go around deleting emails in a long saga in which half the just because they might be asked editorial board of the journal that for at some point. published it resigned. Do you have any regrets? This relates to another issue TD It is regrettable that I’ve always had difficulty with. intemperate language was used I think there are too many in some of the emails. They acted journals – and more are coming as a lightning rod for the storm in climate. So if our critics use which many commentators said the excuse that they can’t get was brewing. The resultant shock papers in scientific journals… felt at UEA, and by Phil in well, there are enough journals particular, will certainly change around. Getting work published the way we work. All at UEA now is not a problem. recognise that we should treat all Some of the emails refer to requests for information equally, repeated freedom of information and not to try to distinguish requests for the CRU’s data. Do you between well-intentioned think there should be limits to FOI requests and those which appear when it comes to science? spurious or mischievous. PJ I think some information With the inquiries over, what’s next? should be exempt from FOI PJ I haven’t been back to a requests. If I do a review for a scientific meeting since early journal I don’t think I should November, but I’ve got one have to release my review. And scheduled later this year. I’m I think we should be given some looking forward to going to it. time to develop a dataset before Interview by Catherine Brahic n releasing it.
and Sumet Sakulsermsuk of the University of Birmingham, UK, have demonstrated an indirect but potentially more efficient way of manipulating atoms. They placed an STM stylus just above a tiny pit in the surface of a silicon wafer, causing electrons from the tip to burrow down and travel as a quantum wave within the material, avoiding surface defects that would otherwise obstruct them (see diagram). “I call it a submarine,” says Palmer. The electrons were able to break the chemical bonds holding
chlorobenzene molecules to the silicon surface up to 10 nanometres from the tip (Physical Review Letters, DOI: 10.1103/ PhysRevLett.105.048301). Being able to drive off these molecules could be the first step to manipulating atoms on the surface. Palmer says the technique could lead to a new way of manufacturing, in which a silicon wafer is patterned with numerous pits or other features where electrons could be injected, and an array of STM tips is used to manipulate many atoms at a time spread over a large distance. Philip Moriarty of the University of Nottingham, UK, says the result is an excellent piece of fundamental science, but points out that the electrons travel in all directions from the stylus tip and cannot be directed to influence specific atoms. He and his colleagues are working instead on creating and breaking single chemical bonds directly with an atomic force microscope, which is normally used to measure interatomic forces. Meanwhile, a group led by Damien Riedel of the University of Paris-South in France has reported using an STM to control the rate of motion of a hydrogen atom on a silicon surface. Their method works up to 2.4 nanometres away from the tip (Physical Review Letters, DOI: 10.1103/PhysRevLett.105.048302).
Eugenie Samuel Reich n
Atomic-scale manipulator Electrons injected below the surface of a silicon wafer can influence atoms or molecules some distance away SURFACE DEFECT SCANNING TUNNELLING MICROSCOPE
SILICON WAFER
An electron travelling as a quantum wave on the surface can be obstructed by defects
CHLOROBENZENE MOLECULE QUANTUM WAVE
If the electron is injected into a pit, it can travel beneath the surface to dislodge molecules up to 10 nanometres away
31 July 2010 | NewScientist | 11
TD We regard emails as ordinary conversations, and some of those we regard as personal and confidential. The FOI act is clearly laudable. But we also believe there is an argument for confidentiality. The trouble is, that is interpreted by some as being somehow sinister, when it clearly is not in the vast majority of cases. US law accepts that emails between colleagues when they’re working on a paper and around peer review should not be disclosable. That came about because of what was described as a potentially chilling effect on research if every single email exchange was released. Phil, did you delete any emails out of concern that they might be the subject of FOI requests? PJ I haven’t deleted any emails
Electron ‘submarines’ help push atoms around IMAGINE a machine that can assemble an object atom by atom. That may be a step closer with the demonstration of electrons moving like a “quantum submarine” inside a material. Manipulating atoms directly is a major goal of nanotechnology, but remains a long way off. The best that has been achieved so far is to push individual atoms around using a scanning tunnelling microscope (STM), a device which can obtain images at the atomic scale using electrons emitted from a stylus just one atom wide at its tip. Now Richard Palmer, Peter Sloan
“A silicon wafer could have numerous pits where that were the subject of FOI electrons can be injected, requests, but I have deleted emails manipulating many atoms” because I just have too many to cope with. I’m deleting 50 every day at the moment. It would be very difficult to guess what might –Jones became a marked man– be asked for in the future so I don’t go around deleting emails in a long saga in which half the just because they might be asked editorial board of the journal that for at some point. published it resigned. Do you have any regrets? This relates to another issue TD It is regrettable that I’ve always had difficulty with. intemperate language was used I think there are too many in some of the emails. They acted journals – and more are coming as a lightning rod for the storm in climate. So if our critics use which many commentators said the excuse that they can’t get was brewing. The resultant shock papers in scientific journals… felt at UEA, and by Phil in well, there are enough journals particular, will certainly change around. Getting work published the way we work. All at UEA now is not a problem. recognise that we should treat all Some of the emails refer to requests for information equally, repeated freedom of information and not to try to distinguish requests for the CRU’s data. Do you between well-intentioned think there should be limits to FOI requests and those which appear when it comes to science? spurious or mischievous. PJ I think some information With the inquiries over, what’s next? should be exempt from FOI PJ I haven’t been back to a requests. If I do a review for a scientific meeting since early journal I don’t think I should November, but I’ve got one have to release my review. And scheduled later this year. I’m I think we should be given some looking forward to going to it. time to develop a dataset before Interview by Catherine Brahic n releasing it.
and Sumet Sakulsermsuk of the University of Birmingham, UK, have demonstrated an indirect but potentially more efficient way of manipulating atoms. They placed an STM stylus just above a tiny pit in the surface of a silicon wafer, causing electrons from the tip to burrow down and travel as a quantum wave within the material, avoiding surface defects that would otherwise obstruct them (see diagram). “I call it a submarine,” says Palmer. The electrons were able to break the chemical bonds holding
chlorobenzene molecules to the silicon surface up to 10 nanometres from the tip (Physical Review Letters, DOI: 10.1103/ PhysRevLett.105.048301). Being able to drive off these molecules could be the first step to manipulating atoms on the surface. Palmer says the technique could lead to a new way of manufacturing, in which a silicon wafer is patterned with numerous pits or other features where electrons could be injected, and an array of STM tips is used to manipulate many atoms at a time spread over a large distance. Philip Moriarty of the University of Nottingham, UK, says the result is an excellent piece of fundamental science, but points out that the electrons travel in all directions from the stylus tip and cannot be directed to influence specific atoms. He and his colleagues are working instead on creating and breaking single chemical bonds directly with an atomic force microscope, which is normally used to measure interatomic forces. Meanwhile, a group led by Damien Riedel of the University of Paris-South in France has reported using an STM to control the rate of motion of a hydrogen atom on a silicon surface. Their method works up to 2.4 nanometres away from the tip (Physical Review Letters, DOI: 10.1103/PhysRevLett.105.048302).
Eugenie Samuel Reich n
Atomic-scale manipulator Electrons injected below the surface of a silicon wafer can influence atoms or molecules some distance away SURFACE DEFECT SCANNING TUNNELLING MICROSCOPE
SILICON WAFER
An electron travelling as a quantum wave on the surface can be obstructed by defects
CHLOROBENZENE MOLECULE QUANTUM WAVE
If the electron is injected into a pit, it can travel beneath the surface to dislodge molecules up to 10 nanometres away
31 July 2010 | NewScientist | 11