Adrian Bachtold

The Project

Quantum probes based on carbon nanotubes.


Adrian Bachtold
Institut de Microelectronica de Barcelona
Centro Nacional Microelectrónica
Universitat Autonoma de Barcelona
Barcelona, Spain



Adrian Bachtold, 33 years old, is currently on the scientific staff at the Catalan Institute of Nanotechnology and the Centro Nacional Microelectrónica in Barcelona, Spain, and Principal Investigator of the Quantum Nano-Electronic Group. From 2001-2005, he was Chargé de recherche CNRS at the Ecole Normale Supérieure in Paris. Bachtold graduated Summa Cum Laude in 1999 with a Ph.D in physics from the University of Basel, Switzerland. Of dual Swiss/French nationality, he completed his postdoctoral research at the University of California at Berkeley, USA, in 1999 and Delft University of Technology, The Netherlands, in 2001. Nearly 1,000 published articles cite his scientific work. He won the bronze medal of the CNRS in 2004.



Project Description

The aim of this project is to take advantage of the unique properties of carbon nanotubes(*) for the fabrication of two ultra-sensitive detectors.

The first detector is designed to probe the electric properties of individual molecules that are subject to perturbations, such as electric field, light or conformational changes. The detection scheme is based on an original approach. Indeed, previous experiments have aimed at contacting individual organic molecules with two electrodes. Problems have quickly appeared due to the poor control of the electrode/molecule interfaces. Here, the molecule is attached to only one electrode, a nanotube. The resistance of the nanotube is measured as a function of a gate voltage, which should be sensitive on the energy spectrum of the molecule. Most importantly, such an approach is expected to be mostly independent on the quality of the interface.

The second type of detector consists of an electromechanical oscillator based on a suspended nanotube for the detection of ultra-low forces and/or extremely fast mechanical vibrations. A new layout based on engineered multiwalled nanotubes is proposed, which may enable force detection at sub-attoNewton resolution. This would surpass the highest force sensitivities that have ever been detected. The new layout may also allow the reach of the quantum limit of motion. Quantum mechanics applied to an oscillator yields an intrinsic fluctuation amplitude, the zero-point motion.

Such an observation in the vibrations of a nanotube would show that the quantum rules of the microscopic world can still be applied to much larger systems that are composed of several thousands of atoms.

(*) Definition - Carbon Nanotubes:
Carbon nanotubes are cylindrical carbon molecules with novel properties that make them potentially useful in a wide variety of applications (eg, nano-electronics, optics, materials applications, etc.). They exhibit extraordinary strength and unique electrical properties, and are efficient conductors of heat. Inorganic nanotubes have also been synthesized. A nanotube (also known as a buckytube) is a member of the fullerene structural family, which also includes buckyballs. Whereas buckyballs are spherical in shape, a nanotube is cylindrical, with at least one end typically capped with a hemisphere of the buckyball structure. Their name is derived from their size, since the diameter of a nanotube is in the order of a few nanometers (approximately 50,000 times smaller than the width of a human hair), while they can be up to several centimeters in length. (Source: Wikipedia)