Nanoobjects microscopy

The diplon system in helium film for IR detecting

V. A. Nikolaenko1,  A. G. Pashchenko2	 
1 - B. Verkin Institute for Low Temperature Physics and Engineering, National Academy of Sciences of Ukraine, 47 Nauka Ave., Kharkiv, 61103, Ukraine
2 - Kharkiv National University of Radio Engineering and Electronics, 14 Nauka Ave, Kharkiv, 61166, Ukraine 
E-mail: nikolaenko@ilt.kharkov.ua

 A new glance on the applying some physical effects and models to practice realization give the modern nano-technologies. One from this object is dipole complex in superfluid helium film - diplon. The dielectric substrate can be charged by positive ions and then the helium film charged by the surface electrons. Because of Coulomb interaction of charges in parabolic potential well the quasi-harmonic spectrum along surface is formed ħ·ω·l  (ħ is Plank’s constant, ω is frequency and l = 1; 2; 3… .). The density of diplons can varied in wide range up to 1015 m-2. The selective spectrum dependents on thickness helium film, d  and the  basic frequency is  ωd2 = 2e2/[(1+εs) md3]  (here e and m are electric charge an mass of electron, accordingly). The energy ħ·ωd depends as  d3/2 and the estimates give the energy scale near 50K at d = 30nm  and ~ 250K at d = 10nm, accordingly. The spectrum corresponds to terahertz (THz) range and can be shifted either to area “soft” or area “hard” radiation by changing the helium film thickness at smooth substrate. The normal directed electromagnetic irradiation corresponding frequency causes change both the electron state in diplon system and the potential relatively substrate. The main electric field of diplon system El  = 2e/[(1+εs) d2]  be in superposition with outside electric field, E. The change  E  leads to adjusting irradiation frequency to harmonic frequency of diplon system. The CCD matrix as substrate with the individual pixels control makes device to read the charge relief under the thin substrate formed by radiation image.

1.	Monarkha Yu.P., Kovdrya Yu. Z.,  Dipol complexes in superfluid helium film //Low Temp.Phys. -1982. – 8. – P.215-218 (in Russian). 
2.	Kovdrya Yu. Z., Mende F.F., Nikolaenko V.A., High-frequency conductivity of electrons above helium film in the regime of localization on substrate potential inhomogeneities // Low Temp.Phys. -1984. – 10. – P.1129-1140 (in Russian).