Manipulating Quantum Dots to Nanometer Precision by Control of Flow

Abstract

We present a method for manipulating preselected quantum dots (QDs) with nanometer precision by flow control. The accuracy of this approach scales more favorably with particle size than optical trapping, enabling more precise positioning of nanoscopic particles. We demonstrate the ability to position a single QD in a 100 microm working region to 45 nm accuracy for holding times exceeding one hour and the ability to take active quantum measurements on the dynamically manipulated QD.

Nanometer positioning of single quantum dots by flow control

“…4a. The autocorrelation integration was taken over 15 minutes and yielded an estimated g 2 (0) = 0.37 ± 0.02 and decay time t d = 22.73 ± 1.07 ns [27]. This clear signature of anti-bunching demonstrates that we are indeed controlling a single QD.…”

“…3. This data has a standard deviation of 19 nm which signifies how precisely we can measure the position of a single QD using subpixel averaging [27].…”

“…(a) Autocorrelation measurement of a single controlled quantum dot obtained from a 15 minute integration with 1 ns binning and exponential fits shown. From the exponential fit we determine g 2 (0) = 0.37 ± 0.02 and decay time td = 22.73 ± 1.07 ns[27]. (b) Time trace fluorescence intermittency as measured from a single QD.a b…”

Confinement of single macromolecules in free solution using a hydrodynamic trap

“…However, confinement and fine-scale manipulation of macromolecules and nanoparticles remains a significant challenge. Currently, particle trapping methods based on acoustic [1][2][3][4] , electrokinetic [5][6][7][8][9][10][11][12][13][14][15] , magnetic [16][17][18] , and optical [19][20][21][22][23][24][25][26][27][28] fields are utilized, but these methods are limited to trapping particles with specific material properties and bulky micron-scale dimensions. [29][30][31] Recently, we developed a new flow-based confinement method that enables 2-D manipulation of single micro and nanoscale particles suspended in aqueous solution.…”

Nanoscale probing of surface plasmons with single quantum dots

“…The ability to position nanoscopic objects at precise locations on a surface is essential for a broad range of applications in the areas of quantum optics, sub-wavelength imaging, and biological sensing. In this talk I will describe a method we have developed for manipulating particles with nanometer accuracy by controlling the flow of the surrounding liquid [1][2][3]. This technique can manipulate a single pre-selected quantum dot to better than 45 nm accuracy and use it as a near field optical sensor that can probe nanoscale photonic structures.…”