公开(公告)号：JPS6412201A

公开(公告)日：1989-01-17

申请号：JP12223288

申请日：1988-05-20

Applicant: IBM

Inventor： BEHA JOHANNES GEORG ,  BLACHA ARMIN UDO ,  CLAUBERG ROLF ,  MOELLER ROLF BERND GEORG ,  POHL WOLFGANG DIETER

IPC: H01J37/00 ,  G01B7/34 ,  G01N23/00 ,  G01N23/227 ,  G01N37/00 ,  G01Q10/00 ,  G01Q20/00 ,  G01Q20/02 ,  G01Q60/10 ,  G01Q60/12 ,  G01Q60/16

Abstract: PURPOSE: To realize femtosecond-order to picosecond-order time resolution and atomic-level space resolution by holding a tunnel chip at a tunnel distance above a sample and applying a tunnel voltage across the gap between the chip and sample, and then, supplying at least one pulsed laser. CONSTITUTION: A tunnel chip 1 is placed at a tunnel distance (namely, at about 1nm) above the surface 2 of a sample 3 to be investigated. A pulsed laser beam (pump beam) 4 is projected upon the surface 2 of the sample 3 from the chip 1 which is separated from the surface 2 by a distance by performing stroboscopic scanning. At every exciting pulse, thermoelectrons are generated at the place of collision and move in the sample 3. The dynamic response of a system including the material of the sample 3 and the electrons moving in the sample 3 is investigated by stroboscopic extraction. When another laser beam 5 is projected upon the surface 2 of the sample 3 near the tunnel chip 1 synchronously to the pump beam 4, the moving thermoelectrons are excited to a higher energy level.

公开(公告)号：DE3772563D1

公开(公告)日：1991-10-02

申请号：DE3772563

申请日：1987-06-22

Applicant: IBM

Inventor： BEHA JOHANNES GEORG ,  BLACHA ARMIN UDO ,  CLAUBERG ROLF ,  MOELLER ROLF BERND GEORG ,  POHL WOLFGANG DIETER

IPC: H01J37/00 ,  G01B7/34 ,  G01N23/00 ,  G01N23/227 ,  G01N37/00 ,  G01Q10/00 ,  G01Q20/00 ,  G01Q20/02 ,  G01Q60/10 ,  G01Q60/12 ,  G01Q60/16 ,  G01N27/00 ,  G01R31/28

Abstract: The tunnel tip (20) of a scanning tunnelling microscope is positioned at tunnel distance with respect to the surface of the sample (27) to be investigated. A predetermined electrical potential is applied across the gap between tunnel tip (20) and sample (27). The tunnelling current is gated by a pulsed laser beam (26) directed at the tunnelling region and/or at the tip (20). Hot electrons in the sample are excited by a laser beam to an energy first below the work-function and caused to travel within the sample. A second laser gates the current in accordance with the pulse patterns. Alternatively, a laser beam changes the resistance of a photoconductive layer (23) arranged between the electrode (22) and associated electronics (24,25).