Magnetic switching element and signal processing device using the same

Abstract

A magnetic switching element according to an example of the present invention includes a magnetic element, first and second electrodes which put the magnetic element therebetween, a current control section which is connected to the first and second electrodes, the current control section controlling a magnetization direction of a magnetization free section in such a manner that a current is made to flow between the magnetization free section and the magnetization fixed section, a movable conductive tube having a fixed end and a free end, and a third electrode connected to the fixed end of the conductive tube. A switching operation is performed in such a manner that a spatial position of the conductive tube is caused to change depending on the magnetization direction of the magnetization free section.

1 . A magnetic switching element comprising: 
 a magnetic element which has a magnetization fixed section whose magnetization direction is fixed, a magnetization free section whose magnetization direction changes due to spin-polarized electrons, and a non-magnetic intermediate layer between the magnetization fixed section and the magnetization free section;    first and second electrodes which puts the magnetic element therebetween;    a current control section which is connected to the first and second electrodes, the current control section controlling the magnetization direction of the magnetization free section in such a manner that a current is made to flow between the magnetization fixed section and the magnetization free section;    a movable conductive tube having a fixed end and a free end;    a magnetic fine particle provided at the conductive tube; and    a third electrode connected to the fixed end of the conductive tube.    
     
     
         2 . The magnetic switching element according to  claim 1 , wherein a state that the magnetic fine particle comes into contact with the first electrode, the second electrode or the magnetic element is defined as an ON state, while a state that the magnetic fine particle is separated from the first electrode, the second electrode or the magnetic element is defined as an OFF state.  
     
     
         3 . The magnetic switching element according to  claim 1 , further comprising a fourth electrode independent of the first, second and third electrodes, 
 wherein a state that the magnetic particles come into contact with the fourth electrode is defined as an ON state, while a state that the magnetic fine particle is separated from the fourth electrode is defined as an OFF state.    
     
     
         4 . The magnetic switching element according to  claim 1 , further comprising a dummy electrode arranged at a position opposite to the third electrode.  
     
     
         5 . The magnetic switching element according to  claim 1 , wherein the magnetic fine particle is arranged at the free end of the conductive tube.  
     
     
         6 . The magnetic switching element according to  claim 1 , wherein the magnetization of the magnetic element is in an anti-parallel state in a state that the current does not flow, while the magnetization of the magnetic element is in a parallel state in a state that the current flows.  
     
     
         7 . The magnetic switching element according to  claim 1 , wherein the magnetization of the magnetic element is in a parallel state in a state that the current does not flow, while the magnetization of the magnetic element is in an anti-parallel state in a state that the current flows.  
     
     
         8 . The magnetic switching element according to  claim 1 , wherein when the current flows in a first direction, the magnetic element remains in a parallel state even though the current is cut off thereafter, while when current flows in a second direction, the magnetic element remains in an anti-parallel state even though the current is cut off thereafter.  
     
     
         9 . The magnetic switching element according to  claim 1 , wherein the magnetization fixed section has an SAF structure, and the magnetization of the magnetization free section is in a heat fluctuation state in a state that the current does not flow, while the magnetization of the magnetization free section heads toward one direction in a state that the current flows.  
     
     
         10 . The magnetic switching element according to  claim 1 , wherein the magnetization fixed section has an SAF structure, and the magnetization of the magnetization free section heads toward one direction in a state that the current flows in a first direction, while the magnetization of the magnetization free section heads toward another direction opposite to the one direction in a state that the current flows in a second direction.  
     
     
         11 . The magnetic switching element according to  claim 1 , wherein the magnetic switching element is in an OFF state in a state that the current does not flow.  
     
     
         12 . The magnetic switching element according to  claim 1 , wherein the magnetic switching element is in an ON state in a state that the current does not flow.  
     
     
         13 . The magnetic switching element according to  claim 1 , wherein the magnetic switching element is in an OFF state in a state that the current flows in a first direction, while the magnetic switching element is in an ON state in a state that the current flows in a second direction.  
     
     
         14 . The magnetic switching element according to  claim 1 , wherein the non-magnetic intermediate layer is composed of a non-magnetic conductive layer.  
     
     
         15 . The magnetic switching element according to  claim 1 , wherein the conductive tube is arranged within a cavity covered with an insulating layer.  
     
     
         16 . A signal processing device comprising: 
 switch units each comprising the magnetic switching element according to  claim 1 ,    wherein a logic circuit is composed of combination of the switch units.    
     
     
         17 . The signal processing device according to  claim 16 , wherein the switch units are stacked on a semiconductor substrate.  
     
     
         18 . A magnetic switching element comprising: 
 a magnetic element which has a magnetization fixed section whose magnetization direction is fixed, a magnetization free section whose magnetization direction changes due to spin-polarized electrons, and a non-magnetic intermediate layer between the magnetization fixed section and the magnetization free section;    first and second electrodes which put the magnetic element therebetween;    a current control section which is connected to the first and second electrodes, the current control section controlling the magnetization direction of the magnetization free section in such a manner that a current is made to flow between the magnetization fixed section and the magnetization free section;    a movable conductive tube having a fixed end and a free end;    a third electrode connected to the fixed end of the conductive tube;    a magnetic fine particle provided at the conductive tube; and    a supporting stand which supports the free end of the conductive tube.    
     
     
         19 . The magnetic switching element according to  claim 18 , wherein a state that the magnetic fine particle comes into contact with the first electrode, the second electrode or the magnetic element is defined as an ON state, while a state that the magnetic fine particle is separated from the first electrode, the second electrode or the magnetic element is defined as an OFF state.  
     
     
         20 . The magnetic switching element according to  claim 18 , further comprising a fourth electrode independent of the first, second and third electrodes, 
 wherein a state that the magnetic particles come into contact with the fourth electrode is defined as an ON state, while a state that the magnetic fine particle is separated from the fourth electrode is defined as an OFF state.    
     
     
         21 . The magnetic switching element according to  claim 18 , wherein the magnetic fine particle is included in the conductive tube.  
     
     
         22 . The magnetic switching element according to  claim 18 , wherein the magnetization of the magnetic element is in an anti-parallel state in a state that the current does not flow, while the magnetization of the magnetic element is in a parallel state in a state that the current flows.  
     
     
         23 . The magnetic switching element according to  claim 18 , wherein the magnetization of the magnetic element is in a parallel state in a state that the current does not flow, while the magnetization of the magnetic element is in an anti-parallel state in a state that the current flows.  
     
     
         24 . The magnetic switching element according to  claim 18 , wherein, when the current flows in a first direction, the magnetic element remains in a parallel state even though the current is cut off thereafter, while when current flows in a second direction, the magnetic element remains in an anti-parallel state even though the current is cut off thereafter.  
     
     
         25 . The magnetic switching element according to  claim 18 , wherein the magnetization fixed section has an SAF structure, and the magnetization of the magnetization free section is in a heat fluctuation state in a state that the current does not flow, while the magnetization of the magnetization free section heads toward one direction in a state that the current flows.  
     
     
         26 . The magnetic switching element according to  claim 18 , wherein the magnetization fixed section has an SAF structure, and the magnetization of the magnetization free section heads toward one direction in a state that the current flows in a first direction, while the magnetization of the magnetization free section heads toward another direction opposite to the one direction in a state that the current flows in a second direction.  
     
     
         27 . The magnetic switching element according to  claim 18 , wherein the magnetic switching element is in an OFF state in a state that the current does not flow.  
     
     
         28 . The magnetic switching element according to  claim 18 , wherein the magnetic switching element is in an ON state in a state that the current does not flow.  
     
     
         29 . The magnetic switching element according to  claim 18 , wherein the magnetic switching element is in an OFF state in a state that the current flows in a first direction, while the magnetic switching element is in an ON state in a state that the current flows in a second direction.  
     
     
         30 . The magnetic switching element according to  claim 18 , wherein the non-magnetic intermediate layer is composed of a non-magnetic conductive layer.  
     
     
         31 . The magnetic switching element according to  claim 18 , wherein the conductive tube is arranged within a cavity covered with an insulating layer.  
     
     
         32 . A signal processing device comprising: 
 switch units each comprising the magnetic switching element according to  claim 18 ,    wherein a logic circuit is composed of combination of the switch units.    
     
     
         33 . The signal processing device according to  claim 32 , wherein the switch units are stacked on a semiconductor substrate.