Physicists 'entangle' microscopic drum's beat with electrical signals

Oct 03, 2013
NIST physicist and JILA Fellow Konrad Lehnert (left) and post-doctoral researcher Tauno Palomaki are in the JILA laboratory where they "entangled" a microscopic mechanical drum with electrical signals. The micro-drum, just 15 micrometers in diameter and 100 nanometers thick, is chilled and manipulated inside the tall tank. Credit: Baxley/JILA

Extending evidence of quantum behavior farther into the large-scale world of everyday life, physicists at the National Institute of Standards and Technology (NIST) have "entangled"—linked the properties of—a microscopic mechanical drum with electrical signals.

The results confirm that NIST's micro-drum could be used as a quantum memory in future quantum computers, which would harness the rules of to solve important problems that are intractable today. The work also marks the first-ever entanglement of a macroscopic oscillator, expanding the range of practical uses of the drum.

Entanglement is a curious feature of the quantum world once believed to occur only at atomic and smaller scales. In recent years, scientists have been finding it in larger systems. Entanglement has technological uses. For instance, it is essential for operations such as correcting errors, and for of data from one place to another.

The experiments, described Oct. 3, 2013, in Science Express, were performed at JILA, a joint institute of NIST and the University of Colorado Boulder.

NIST introduced the aluminum micro-drum in 2011 and earlier this year suggested it might be able to store data in quantum computers. The drum—just 15 micrometers in diameter and 100 nanometers thick—features both mechanical properties (such as vibrations) and quantum properties (such as the ability to store and transfer individual quanta of energy).

The drum is part of an electromechanical circuit that can exchange certain quantum states between the waveform of a microwave pulse and vibration in the drum. In the latest JILA experiment, a microwave signal "cooled" the drum to a very low energy level, just one unit of vibration, in a way analogous to some laser-cooling techniques. Then another signal caused the drum's motion to become entangled with a microwave pulse that emerged spontaneously in the system.

The drum stored the quantum information in the form of vibrational energy for at least 10 microseconds, long enough to be useful in experiments. Then the same type of that cooled the drum was used to transfer the state stored in the drum to a second microwave pulse.

Researchers measured the properties of the two microwave pulses—specific points on the curves of the travelling waves—and found that the results were strongly correlated over 10,000 repetitions of the experiment. The evidence of comes from the fact that measuring the first microwave pulse allowed scientists to anticipate the characteristics of the second pulse with greater accuracy than would otherwise be expected. The correlations between the two pulses indicated that the first pulse was entangled with the drum and the second pulse encoded the drum's quantum state.

The results suggest that the drum, in addition to its potential as a device, also could be used to generate in microwaves, to convert one form of to an otherwise incompatible form, and to sense tiny forces with improved precision.

Explore further: The importance of three-way atom interactions in maintaining coherence

More information: T.A. Palomaki, J.D. Teufel, R.W. Simmonds and K.W. Lehnert. Entangling mechanical motion with microwave fields. Science Express. Oct. 3, 2013.

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Macksb
1 / 5 (4) Oct 03, 2013
This is consistent with Art Winfree's law of coupled oscillators, which I have applied to physics in many prior Physorg posts. Circa 1967, Winfree posited that all periodic (limit cycle) oscillators have a tendency to couple under the right circumstances. Frequency of oscillation and proximity of oscillators are two key variables related to the onset of coupling. In physics, phase transitions work the same way, driven by changes in temperature (frequency) and proximity (pressure). Planck's quantum itself is a periodic oscillation.

Drums are oscillators. Here, the oscillations are periodic and of low, regular frequency. Entanglement equals coupling.

"Entanglement is a curious feature of the quantum world once believed to occur only at atomic and smaller scales." Not by me, and not by Art Winfree. Periodic oscillators of all dimensions tend to synchronize their oscillations and couple in various precise Winfree patterns.

How long do I have to keep beating this drum?
vacuum-mechanics
1 / 5 (5) Oct 03, 2013
The results confirm that NIST's micro-drum could be used as a quantum memory in future quantum computers, which would harness the rules of quantum physics to solve important problems that are intractable today. The work also marks the first-ever entanglement of a macroscopic oscillator, expanding the range of practical uses of the drum.
Entanglement is a curious feature of the quantum world once believed to occur only at atomic and smaller scales. In recent years, scientists have been finding it in larger systems. Entanglement has technological uses. For instance, it is essential for quantum computing operations such as correcting errors, and for quantum teleportation of data from one place to another.

It seems that there is much research on the application of quantum mechanics - but not on the theoretical realm, maybe because of its mystery; actually it is not so difficult as we thought, this may be the guide way….

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