Thermoelectric device utilizing non-zero berry curvature

Abstract

Thermoelectric devices and methods of using thermoelectric devices. A thermoelectric device includes a thermoelectric element comprised of a material having a non-zero Berry curvature. The device may operate as a Nernst generator that generates electricity in response to application of a temperature gradient to the thermoelectric element, or as an Ettingshausen cooler that pumps heat into or out of an object to be heated or cooled in response to application of a current to the thermoelectric element. In either application, the non-zero Berry curvature of the material allows the device to operate without an externally applied magnetic field.

1 - 20 . (canceled) 
     
     
         21 . A method of generating electricity comprising:
 providing a temperature gradient across a first dimension of a thermoelectric element including a material having a non-zero Berry curvature along the first dimension;   generating a voltage gradient along a second dimension of the thermoelectric element aligned with a cross-product of the temperature gradient and the non-zero Berry curvature; and   coupling a voltage provided by the voltage gradient to an electrical load.   
     
     
         22 . The method of  claim 21  wherein providing the temperature gradient across the first dimension of the thermoelectric element comprises:
 coupling a first side of the thermoelectric element to a heat source; and 
 coupling a second side of the thermoelectric element to a heat sink, the second side located a first distance from the first side along a third dimension transverse to both the first dimension and second dimension. 
 
     
     
         23 . The method of  claim 22  further comprising:
 applying a magnetic field aligned with the non-zero Berry curvature to the thermoelectric element. 
 
     
     
         24 . The method of  claim 21  wherein the material is a Weyl semimetal. 
     
     
         25 . The method of  claim 21  wherein the temperature gradient is orthogonal to the non-zero Berry curvature. 
     
     
         26 . A method of pumping heat into or out of a thermal load, comprising:
 passing a current through a thermoelectric element including a material having a non-zero Berry curvature along a first dimension such that the current flows across the first dimension;   generating a temperature gradient along a second dimension of the thermoelectric element aligned with a cross-product of the current and the non-zero Berry curvature; and   coupling the temperature gradient to the thermal load.   
     
     
         27 . The method of  claim 26  wherein coupling the temperature gradient to the thermal load comprises:
 coupling a first side of the thermoelectric element to a heat sink; and 
 coupling a second side of the thermoelectric element to an object to be cooled or warmed, the second side located a first distance from the first side along the second dimension. 
 
     
     
         28 . The method of  claim 27  wherein passing the current through the thermoelectric element in a first direction cools the object, and passing the current in a second direction opposite the first direction warms the object. 
     
     
         29 . The method of  claim 26  further comprising:
 applying a magnetic field aligned with the non-zero Berry curvature to the thermoelectric element. 
 
     
     
         30 . The method of  claim 26  wherein the material is a Weyl semimetal. 
     
     
         31 . The method of  claim 26  wherein the non-zero Berry curvature is orthogonal to both the temperature gradient and the current. 
     
     
         32 . A thermoelectric device comprising:
 a thermoelectric element including a material having a non-zero Berry curvature along a first dimension of the thermoelectric element;   a first thermal coupler thermally coupled to a first side of the thermoelectric element;   a second thermal coupler thermally coupled to a second side of the thermoelectric element, the second side located a first distance from the first side along a second dimension transverse to the first dimension;   a first terminal electrically coupled to a third side of the thermoelectric element; and   a second terminal electrically coupled a fourth side of the thermoelectric element, the fourth side located a second distance from the third side along a third dimension aligned with a cross-product of the second dimension and the non-zero Berry curvature.   
     
     
         33 . The thermoelectric device of  claim 32  wherein the thermoelectric element generates a voltage across the first and second terminals in response to an application of a temperature gradient across the first and second thermal couplers. 
     
     
         34 . The thermoelectric device of  claim 32  wherein the thermoelectric element generates a temperature gradient across the first and second thermal couplers in response to an application of an electrical current through the first and second terminals. 
     
     
         35 . The thermoelectric device of  claim 32  wherein the non-zero Berry curvature is orthogonal to a temperature gradient to which the thermoelectric element is exposed or the thermoelectric element generates. 
     
     
         36 . The thermoelectric device of  claim 32  wherein:
 the first thermal coupler is configured to thermally couple the first side to a heat source; and 
 the second thermal coupler is configured to thermally couple the second side to a heat sink, 
 wherein a voltage is generated between the third and fourth sides in response to application of a temperature gradient between the first thermal coupler and the second thermal coupler. 
 
     
     
         37 . The thermoelectric device of  claim 32  further comprising:
 a magnet configured to provide a magnetic field aligned with the non-zero Berry curvature to the thermoelectric element. 
 
     
     
         38 . The thermoelectric device of  claim 32  wherein the material is a Weyl semimetal. 
     
     
         39 . The thermoelectric device of  claim 38  wherein the Weyl semimetal breaks time-reversal symmetry.