# US 5,705,824 A · Field controlled current modulators based on tunable barrier strengths > Agents: this data is available as JSON from the patentgrep API and MCP server — see https://patentgrep.com/llms.txt - Number: US 5,705,824 A - Document ID: US5705824A - Status: Granted - Kind: A - Application number: 08/497,672 - Filed: 1995-06-30 - Granted: 1998-01-06 - Earliest claimed: 1995-06-30 - Assignees: The United States of America as represented by the Secretary of the Army - Inventors: Gerald J. Lafrate; Jun He; Mitra Dutta; Michael A. Stroscio - Web page: https://patentgrep.com/patent/US5705824A ## CPC - H10D 48/383: {Quantum effect devices, e.g. of devices using quantum reflection, diffraction or interference effects} - B82Y 10/00: Nanotechnology for information processing, storage or transmission, e.g. quantum computing or single electron logic - H10D 12/00: Bipolar devices controlled by the field effect, e.g. insulated-gate bipolar transistors [IGBT] - H10D 30/43: having one-dimensional [1D] charge carrier gas channels, e.g. quantum wire FETs or transistors having 1D quantum-confined channels - H10D: INORGANIC ELECTRIC SEMICONDUCTOR DEVICES - B82Y: SPECIFIC USES OR APPLICATIONS OF NANOSTRUCTURES; MEASUREMENT OR ANALYSIS OF NANOSTRUCTURES; MANUFACTURE OR TREATMENT OF NANOSTRUCTURES ## Abstract A carrier transport media is doped with impurities or includes barrier structures within or on the carrier transport media and a sinusoidally alternating external electric field(s) with frequencies equal to the Bloch frequency divided by an integer is applied to the carrier transport media to alter the effective barriers of the impurities or barrier structures to an arbitrarily large potential compared to the zero field barrier potential. The various impurities or barrier structures are band engineered and deposited, grown or implanted in the carrier transport media and can take any form such as barrier layers in or on the transport media, laterally induced barriers, and impurities or defects in the carrier transport media. The application of time-dependent external fields across a length of nanoscale or mesoscopic structure leads to an effective renominalization of the barrier potential strengths when the frequency of the applied electric field multiplied by an integer is equal to the Bloch frequency. Under these conditions the transmission probability is altered and the current ratio, i.sub.2 /i.sub.1, will be modulated strongly. ## Claims ### Claim 1 A quantum scale current modulator comprising: a quantum sized electron transport media made of a semiconductor material; means to provide a potential barrier within said electron transport media; and means to apply an alternating external electric field to said electron transport media wherein said alternating external electric field is applied at a frequency equal to a Bloch frequency divided by an integer and said alternating external electric field alters said potential barrier. ### Claim 2 (depends on 1) The current modulator of claim 1 wherein the means to apply an alternating external electric field includes a means to apply a plurality of alternating external electric fields. ### Claim 3 (depends on 1) A current modulator of claim 1 wherein the means to provide a potential barrier to said transport media includes at least two quantum barrier regions disposed longitudinally within said transport media. ### Claim 4 (depends on 1) A current modulator of claim 1 wherein the means to provide a potential barrier to said transport media includes a conductor disposed laterally on said transport media and parallel to a current flow within said transport media. ### Claim 5 (depends on 4) A current modulator of claim 4 wherein the current transport media includes a two dimensional electron gas. ### Claim 6 (depends on 1) A current modulator of claim 1 wherein the means to provide a potential barrier to said transport media includes a conductor disposed laterally on said transport media and perpendicular to a current flow within said transport media. ### Claim 7 (depends on 6) A current modulator of claim 6 wherein the current transport media includes a two dimensional electron gas. ### Claim 8 (depends on 1) A current modulator of claim 1 wherein the means to provide a potential barrier to said transport media includes a plurality of impurities disposed within said transport media, the plurality of impurities having a predetermined potential barrier strength. ### Claim 9 (depends on 8) A current modulator of claim 8 wherein the said transport media includes at least one entrance plane and one exit plane. ### Claim 10 (depends on 8) A current modulator of claim 8 wherein said transport media includes a plurality of entrance and exit planes. ### Claim 11 A logic circuit comprising: a quantum sized electron transport media made of a semiconductor material; means to provide a potential barrier within said electron transport media; and means to apply an alternating external electric field to said electron transport media wherein said alternating external electric field is applied at a frequency equal to a Bloch frequency divided by an integer and said alternating external electric field alters said potential barrier. ### Claim 12 (depends on 11) A logic circuit of claim 11 wherein the means to provide a potential barrier to said transport media includes a plurality of impurities disposed within said transport media, the plurality of impurities having a predetermined potential barrier strength. ### Claim 13 (depends on 12) A logic circuit of claim 12 wherein the said transport media includes at least one entrance plane and one exit plane. ### Claim 14 (depends on 12) A logic circuit of claim 12 wherein said transport media includes a plurality of entrance and exit planes.