# US 8,680,488 B2 · System and method for producing and using multiple electron beams with quantized orbital angular momentum in an electron microscope > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 8,680,488 B2 - Document ID: US8680488B2 - Status: Granted - Kind: B2 - Application number: 13/372,914 - Filed: 2012-02-14 - Published: 2012-06-21 - Granted: 2014-03-25 - Earliest claimed: 2012-02-14 - Applicants: Benjamin McMorran - Inventors: Benjamin McMorran - Web page: https://patentgrep.com/patent/US8680488B2 ## CPC - H01J 37/28: with scanning beams {(H01J37/268, H01J37/292, H01J37/2955 take precedence)} - H01J 2237/06383: Spin polarised electron sources - H01J 2237/24557: Spin polarisation (particles) - H01J 2237/2614: Holography or phase contrast, phase related imaging in general, e.g. phase plates - H01J 2237/2802: Transmission microscopes - H01J: ELECTRIC DISCHARGE TUBES OR DISCHARGE LAMPS (spark-gaps H01T; electric arc lamps H05B31/00; particle accelerators H05H) ## Abstract A system and method for using electron beams with engineered phase dislocations as scanned probes in electron probe beam instruments such as scanning transmission electron microscopes. These types of electron beams have unique properties and can provide better information about a specimen than conventional electron beams. Phase dislocations may be created based on a pattern disposed on a nanoscale hologram, which may be placed in the electron optical column of the electron probe beam instrument. When an electron beam from the instrument is directed onto the hologram, phase dislocations may be imprinted onto the electron beam when electrons are diffracted from these holograms. For example, electron probe beams with spiral phase dislocations may occur. These spiral phase dislocations are formed using a hologram with a fork-patterned grating. Spiral phase dislocations may be used to provide magnetic contrast images of a specimen. ## Claims ### Claim 1 A system for producing and using multiple electron beams with quantized orbital angular momentum, the system comprising: a nanoscale diffractive hologram device having a pattern disposed therein; an illumination element configured to illuminate the diffractive hologram device with electrons, thus causing said electrons to diffract into at least one electron beam having phase dislocations based on the pattern of said diffractive hologram device; and wherein the diffractive hologram device is configured to be placed in an electron optical column of an electron probe beam instrument such that the at least one electron beam having phase dislocations is configured to be directed onto a specimen. ### Claim 2 (depends on 1) The system of claim 1, wherein the hologram is a forked grating hologram, and the phase dislocations are spiral phase dislocations. ### Claim 3 (depends on 1) The system of claim 1, wherein the diffractive hologram is permanently imprinted onto a condenser lens aperture for a scanning transmission electron microscope. ### Claim 4 (depends on 1) The system of claim 1, wherein the electron probe beam instrument is a scanning electron microscope, a scanning transmission electron microscope or a spectroscope. ### Claim 5 (depends on 1) The system of claim 1, wherein the nanoscale diffractive hologram is composed of silicon nitride, platinum, carbon thin film, diamond thin film or silicon. ### Claim 6 (depends on 1) The system of claim 1, wherein the hologram is placed between an electron source and the specimen in a scanning electron microscope. ### Claim 7 (depends on 1) The system of claim 1, wherein the hologram is placed in the condenser aperture of a scanning transmission electron microscope. ### Claim 8 (depends on 1) The system of claim 1, wherein the specimen is magnetic. ### Claim 9 (depends on 1) The system of claim 1, wherein the pattern of the diffractive hologram is configured to produce, when illuminated, a Hermite Gaussian electron beam with either vertically-oriented edge-type wavefront dislocations or horizontally-oriented edge-type wavefront dislocations. ### Claim 10 (depends on 1) The system of claim 1, wherein the pattern of the diffractive hologram is configured to produce, when illuminated, a Hermite Gaussian electron beam with both vertically-oriented and horizontally-oriented edge-type wavefront dislocations. ### Claim 11 (depends on 1) The system of claim 1, wherein the pattern of the diffractive hologram is configured to produce, when illuminated, an electron beam with superposed positive and negative orbital angular momentum states. ### Claim 12 (depends on 1) The system of claim 1, further comprising: a detection device configured to detect one or more beam property-dependent signals generated when the at least one electron beam having phase dislocations is directed onto the specimen. ### Claim 13 A system for producing and using multiple electron beams with quantized orbital angular momentum, the system comprising: a nanoscale diffractive hologram having a pattern disposed therein; and an electron probe beam instrument having an illumination element, the illumination element being configured to illuminate the diffractive hologram device with electrons, thus causing said electrons to diffract into at least one electron beam having phase dislocations based on the pattern of said diffractive hologram device, wherein the diffractive hologram device is placed in the electron optical column of the electron probe beam instrument such that the at least one electron beam having phase dislocations is configured to be directed onto a specimen. ### Claim 14 (depends on 13) The system of claim 13, wherein the hologram is a forked grating hologram, and the phase dislocations are spiral phase dislocations. ### Claim 15 (depends on 13) The system of claim 13, wherein the diffractive hologram is permanently imprinted onto a condenser lens; and the electron probe beam instrument is a scanning transmission electron microscope. ### Claim 16 (depends on 13) The system of claim 13, wherein the electron probe beam instrument is a scanning electron microscope, a scanning transmission electron microscope or a spectroscope. ### Claim 17 (depends on 13) The system of claim 13, wherein the nanoscale diffractive hologram is composed of silicon nitride, platinum, carbon thin film, diamond thin film or silicon. ### Claim 18 (depends on 13) The system of claim 13, wherein the hologram is placed between a first condenser lens and a second condenser lens of a scanning electron microscope. ### Claim 19 (depends on 13) The system of claim 13, wherein the specimen is composed of iron, cobalt or nickel. ### Claim 20 (depends on 13) The system of claim 13, wherein the pattern of the diffractive hologram is configured to produce, when illuminated, a Hermite Gaussian electron beam with either vertically-oriented edge-type wavefront dislocations or horizontally-oriented edge-type wavefront dislocations. ### Claim 21 (depends on 13) The system of claim 13, wherein the pattern of the diffractive hologram is configured to produce, when illuminated, a Hermite Gaussian electron beam with both vertically-oriented and horizontally-oriented edge-type wavefront dislocations. ### Claim 22 (depends on 13) The system of claim 13, wherein the pattern of the diffractive hologram is configured to produce, when illuminated, an electron beam with superposed positive and negative orbital angular momentum states. ### Claim 23 (depends on 13) The system of claim 13, further comprising: a detection device configured to detect one or more beam property-dependent signals generated when the at least one electron beam having phase dislocations is directed onto the specimen. ### Claim 24 A method for producing and using multiple electron beams with quantized orbital angular momentum, the method comprising: providing a nanoscale diffractive hologram having a pattern disposed therein, placing the nanoscale diffractive hologram into the electron optical column of an electron probe beam instrument; illuminating the diffractive hologram device with electrons, thus causing said electrons to diffract into at least one electron beam having phase dislocations based on the pattern of said diffractive hologram device; causing the at least one electron beam having phase dislocations to be directed onto a specimen. ### Claim 25 (depends on 24) The method of claim 24, wherein the electron probe beam instrument is a scanning transmission electron microscope. ### Claim 26 (depends on 24) The method of claim 24, wherein the hologram device is a forked grating hologram, and the phase dislocations are spiral phase dislocations. ### Claim 27 (depends on 24) The method of claim 24, wherein the nanoscale diffractive hologram is composed of silicon nitride, platinum, carbon thin film, diamond thin film or silicon. ### Claim 28 (depends on 24) The method of claim 24, wherein the specimen is composed of iron, cobalt or nickel.