A new technique can measure how long a single atom can hold information and allows researchers to actually record, study, and visualize the magnetism of individual atoms at speeds 1 million times faster than previously possible.
To perform this breakthrough, scientists employed a Scanning Tunneling Microscope—a technology nearly three decades old. Scientists at IBM recently published their findings in the Sept. 24 edition of the journal Science.
“The technique has great potential because it is applicable to many types of physics happening on the nanoscale,” said IBM Research scientist, Sebastian Loth in a press release.
Scientists say that this new technique could soon lead to engineering improvements in applications such as solar cells, information storage technologies, and quantum computers—creating machines with the potential to perform advanced computations not possible today.
Researchers explain that the magnetic spin of an atom changes at a speed so fast that previously available Scanning Tunneling Microscope techniques could not keep pace. The new technique utilizes the microscope like a high-speed camera, recording time-dependent behavior stroboscopically. Scientists say the result is similar to time lapse photography.
Researchers employed an alternating voltage technique called “pump-probe” to obtain their measurements. Using a fast voltage pulse (pump), scientists excite the atom, while a subsequent weaker voltage pulse (probe) measures the orientation of the atom’s magnetism at a certain time following the excitation. The time delay between the two pulses sets the frame time of each measurement.
To perform this breakthrough, scientists employed a Scanning Tunneling Microscope—a technology nearly three decades old. Scientists at IBM recently published their findings in the Sept. 24 edition of the journal Science.
“The technique has great potential because it is applicable to many types of physics happening on the nanoscale,” said IBM Research scientist, Sebastian Loth in a press release.
Scientists say that this new technique could soon lead to engineering improvements in applications such as solar cells, information storage technologies, and quantum computers—creating machines with the potential to perform advanced computations not possible today.
Researchers explain that the magnetic spin of an atom changes at a speed so fast that previously available Scanning Tunneling Microscope techniques could not keep pace. The new technique utilizes the microscope like a high-speed camera, recording time-dependent behavior stroboscopically. Scientists say the result is similar to time lapse photography.
Researchers employed an alternating voltage technique called “pump-probe” to obtain their measurements. Using a fast voltage pulse (pump), scientists excite the atom, while a subsequent weaker voltage pulse (probe) measures the orientation of the atom’s magnetism at a certain time following the excitation. The time delay between the two pulses sets the frame time of each measurement.
This pulse delay is then varied step-by-step and the average magnetic motion is recorded in small time increments. Scientists alternate the voltage pulses about 100,000 times for each time increment. It may sound like a lot, but all this atomic scale action is accomplished in less than one second.
To perform this experiment, researchers deposited iron atoms onto an insulating layer one atom thick, supported on a copper crystal. Scientists selected such a surface to allow the atoms to be probed electrically while retaining their magnetism.
The iron atoms were positioned with atomic precision next to nonmagnetic copper atoms in order to control the interaction of the iron with the local environment of nearby atoms.
Researchers measured the resulting structures under the influence of several magnetic fields, revealing the speed at which they change their magnetic orientation in relation to the magnetic field they experienced.
Scientists say that this shows how atoms “relax” by means of quantum mechanical tunneling of the atom’s magnetic moment—a process where the atom’s magnetism can reverse its direction without passing through intermediate orientations.
This insight may allow scientists to soon engineer the magnetic lifetime of atoms to create future spintronic devices. Atoms with longer magnetic lifetimes would retain their magnetic state, while atoms designed with shorter magnetic lifetimes could switch to a new magnetic state.
To perform this experiment, researchers deposited iron atoms onto an insulating layer one atom thick, supported on a copper crystal. Scientists selected such a surface to allow the atoms to be probed electrically while retaining their magnetism.
The iron atoms were positioned with atomic precision next to nonmagnetic copper atoms in order to control the interaction of the iron with the local environment of nearby atoms.
Researchers measured the resulting structures under the influence of several magnetic fields, revealing the speed at which they change their magnetic orientation in relation to the magnetic field they experienced.
Scientists say that this shows how atoms “relax” by means of quantum mechanical tunneling of the atom’s magnetic moment—a process where the atom’s magnetism can reverse its direction without passing through intermediate orientations.
This insight may allow scientists to soon engineer the magnetic lifetime of atoms to create future spintronic devices. Atoms with longer magnetic lifetimes would retain their magnetic state, while atoms designed with shorter magnetic lifetimes could switch to a new magnetic state.
