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Angus MacKinnon |
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Cavendish Lab, Cambridge |
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Blackett Lab., Imperial College, London |
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Miles P Blencowe |
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Dartmouth College, USA |
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Andrew D Armour |
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University of Nottingham |
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Caltech – Roukes |
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http://www.its.caltech.edu/~nano/ |
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Cornell – Craighead |
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http://www.hgc.cornell.edu/index.html |
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UCSB – Cleland |
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http://www.qi.ucsb.edu/cleland/ |
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Munich – Blick |
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http://www.nano.physik.uni-muenchen.de/Blick/Blick.html |
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Nanomechanics |
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Yoctocalorimetry |
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Spin Physics |
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Quantum Computing |
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Nanotubes |
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Peapods |
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Computational Molecular Biology |
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Single Phonons |
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Squeezed Phonons |
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Quantum Shuttle |
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Which-Path devices |
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MEMS |
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NEMS |
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Entanglement |
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Universal limits |
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Mechanical Systems |
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Free standing quantum wires |
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Heat & phonon flow |
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Machines |
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Electromechanical Devices |
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Which-way devices |
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Quantum shuttle |
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Entanglement |
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Measuring single phonons |
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Typical phonon energy – 10-24J = 1
Yoctojoule |
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2 Measurements |
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Thermal Conductivity |
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Thermal Decay |
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Gears locked together. |
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Incompatible angular momentum quantisation. |
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Is this compatible with macroscopic behaviour? |
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2 Gears: |
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Simplified – 1 Driven Gear |
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Simple Hamiltonian |
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Rotating Frame |
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Try |
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Only coupled for |
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Compare with |
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No. of states in BZ = No. of teeth |
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Angular Group Velocity |
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Finite V – Finite Angular Group Velocity |
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Except at |
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But
this condition is almost certainly not fulfilled. |
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Why should
be an integer? |
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But |
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1st Brillouin Zone: |
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Tunnelling except: |
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Quantisation of angular momentum not generally
consistent with |
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Driving frequency |
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Other gears |
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>2 Gears |
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No solutions except for special cases. |
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Finite Temperature |
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Need |
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Shuttle is self-driving |
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If potential difference big enough |
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Sensitive to dissipation mechanism |
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I-V Characteristic quickly washed out at finite T. |
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How to calculate transit time? |
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How to avoid negative delay times? |
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Current standard? |
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Quantum Measurement |
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Complementarity |
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Interference |
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Entanglement |
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Schrödinger’s cat |
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No change in the state of the cantilever |
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Aharonov-Bohm interference fringes |
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Cantilever state changes |
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Fringes destroyed |
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No non-destructive measurements |
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But |
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What about coherent coupling to the cantilever? |
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Dwell time on dot » resonant frequency |
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Destroyed by coupling of cantilever to the
environment |
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Need a high Q cantilever |
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Dissipation not well understood |
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Simple nanomechanical devices |
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now
being made. |
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Nature got there first |
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lots of biological examples |
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Science fiction? |
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Micro machines to go around the bloodstream
fixing the body |
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Lots of interesting new physics. |
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Notes
