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US 8,912,821 B2Granted
Logic cells based on spin diode and applications of same
AssigneeNorthwestern University
InventorsJoseph S. Friedman, Nikhil Rangaraju, Yehea Ismail, Bruce W. Wessels
Life of this patent
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Abstract
In one aspect, the invention relates to logic cells that utilize one or more of spin diodes. By placing one or two control wires on the side of the spin diodes to generate magnetic fields in the spin diodes due to input currents, the logic cell can be changed from one logic gate to another logic gate. The unique feature leads to field logic devices in which simple instructions can be used to construct a whole new set of logic gates.
Claims38
A logic cell, comprising:
- (a) a spin diode having a non-magnetic semiconductor layer and a magnetic semiconductor layer disposed on the non-magnetic semiconductor layer, wherein the spin diode is configured such that under a forward bias, when a magnetic field applied to the spin diode is less than a threshold value, the spin diode is in a conductive state in which electric current flows through the spin diode, and when the magnetic field applied to the spin diode is greater than the threshold value, the spin diode is in a resistive state in which the electric current flowing through the spin diode is substantially reduced;
- (b) a voltage supply wire oriented along a first direction parallel to the magnetic semiconductor layer of the spin diode and positioned on the magnetic semiconductor layer for connecting the magnetic semiconductor layer to a voltage supply VDD;
- (c) a first control wire for receiving a first input current and a second control wire for receiving a second input current, wherein the first control wire and the second control wire are oriented in parallel along the first direction and positioned on two sides of the spin diode and the voltage supply wire, such that when the first input current flows through the first control wire, the first input current induces a first magnetic field B1 greater than the threshold value in the spin diode, and when the second input current flows through the second control wire, the second input current induces a second magnetic field B2 greater than the threshold value in the spin diode;
- and
- (d) an output wire oriented along the first direction and positioned on the non-magnetic semiconductor layer of the spin diode for outputting a logic “0” or “1” responsive to the first input current and the second input current.
2 more elements
A logic cell, comprising:
- (a) a spin diode having a non-magnetic semiconductor layer and a magnetic semiconductor layer disposed on the non-magnetic semiconductor layer, wherein the spin diode is configured such that under a forward bias, when a magnetic field applied to the spin diode is less than a threshold value, the spin diode is in a conductive state in which electric current flows through the spin diode, and when the magnetic field applied to the spin diode is greater than the threshold value, the spin diode is in a resistive state in which the electric current flowing through the spin diode is substantially reduced;
- (b) a voltage supply wire oriented along a first direction parallel to the magnetic semiconductor layer of the spin diode and positioned on the magnetic semiconductor layer for connecting the magnetic semiconductor layer to a voltage supply VDD;
- (c) a first control wire for receiving a first input current, wherein the first control wire is oriented along the first direction and positioned on one side of the spin diode and the voltage supply wire, such that when the first input current flows through the first control wire, the first input current induces a first magnetic field B1 greater than the threshold value in the spin diode;
- and
- (d) an output wire oriented along the first direction and positioned on the non-magnetic semiconductor layer of the spin diode for outputting a logic “0” or “1” responsive to the first input current.
2 more elements
A logic cell, comprising:
- (a) first, second, third, fourth, fifth and sixth spin diodes, each spin diode having a cathode and an anode, wherein each of the first, second, third, fourth and fifth spin diodes has a first control wire and a second control wire oriented in parallel and positioned on two sides of the spin diode, and the sixth spin diode has a control wire positioned on one side of the sixth spin diode, configured such that
- for each spin diode, under a forward bias, when a magnetic field applied to the spin diode is less than a threshold value, the spin diode is in a conductive state in which electric current flows through the spin diode, and when the magnetic field applied to the spin diode is greater than the threshold value, the spin diode is in a resistive state in which the electric current flowing through the spin diode is substantially reduced;
- when a control current flows through one of the first and second control wires of each of the first, second, third, fourth and fifth spin diodes, the control current induces a magnetic field greater than the threshold value in the spin diode;
- for each of the first, second and third spin diodes, a second control current is configured to flow through the second control wire in an opposite direction to a first control current flowing in the first control wire such that when the first control current flows through the first control wire and the second input current flows through the second control wire simultaneously, the first magnetic field induced by the first control current adds to the second magnetic field induced by the second control current to generate an added magnetic field greater than the threshold value in the spin diode, thereby implementing a logic NOR gate;
- for each of the fourth and fifth spin diodes, the second control current is configured to flow through the second control wire in the same direction as the first control current flowing in the first control wire such that when the first control current flows through the first control wire and the second control current flows through the second control wire simultaneously, the first magnetic field induced by the first control current nullifies the second magnetic field induced by the second control current to generate a subtracted magnetic field less than the threshold value in the spin diode, thereby implementing a logic XNOR gate;
- and
- for the sixth diode, when a control current flows through the control wire of the sixth spin diode, the control current induces a magnetic field greater than the threshold value in the sixth spin diode, thereby implementing a logic inverter,
- wherein a second end of the first control wire of the first spin diode is electrically connected to a first end of the first control wire of the third spin diode, wherein a second end of the second control wire of the first spin diode is electrically connected to a first end of the first control wire of the second spin diode, wherein a second end of the first control wire of the second spin diode is electrically connected to a first end of the first control wire of the fifth spin diode, wherein a second end of the second control wire of the second spin diode is electrically connected to a first end of the second control wire of the third spin diode, wherein a second end of the first control wire of the third spin diode is electrically connected to a first end of the first control wire of the fourth spin diode, wherein a second end of the second control wire of the third spin diode is electrically connected to a first end of the second control wire of the fourth spin diode, wherein the cathodes of the first, second and third spin diodes are electrically connected to a first end of the control wire of the sixth spin diode, and wherein the cathode of the fourth spin diode is electrically connected to a first end of the second control wire of the fifth spin diode;
- (b) a first input terminal electrically connected to a first end of the first control wire of the first spin diode for providing a first input current, IA;
- (c) a second input terminal electrically connected to a first end of the second control wire of the first spin diode for providing a second input current, IB;
- (d) a third input terminal electrically connected to a first end of the second control wire of the second spin diode for providing a third input current, IC;
- (e) a first voltage supply electrically connected to the anodes of the first, second, third, fourth and fifth spin diodes for providing a first supply voltage, VDD1;
- (f) a second voltage supply electrically connected to the anode of the sixth spin diode for providing a second supply voltage, VDD2;
- (g) a sum output terminal electrically connected to the cathode of the fifth spin diode for outputting a sum output signal of a logic “0” or “1” responsive to the first input current IA, the second input current IB, and the third input current IC;
- and
- (h) a carry-out output terminal electrically connected to the cathode of the sixth spin diode for outputting a carry-out output signal of the logic “0” or “1” responsive to the first input current IA, the second input current IB, and the third input current IC.
13 more elements
A logic cell, comprising:
- (a) first and second spin diodes, each of the first and second spin diodes having a cathode and an anode, and a first control wire and a second control wire oriented in parallel and positioned on two sides of the spin diode, configured such that
- under a forward bias, when a magnetic field applied to the spin diode is less than a threshold value, the spin diode is in a conductive state in which electric current flows through the spin diode, and when the magnetic field applied to the spin diode is greater than the threshold value, the spin diode is in a resistive state in which the electric current flowing through the spin diode is substantially reduced;
- when a control current flows through one of the first and second control wires, the control current induces a magnetic field greater than the threshold value in the spin diode;
- and
- when a first control current flows through the first control wire in an opposite direction to a second control current flowing through the second control wire simultaneously, the first magnetic field induced by the first control current adds to the second magnetic field induced by the second control current to generate an added magnetic field greater than the threshold value in the spin diode, thereby implementing a logic NOR gate, wherein the cathode of the first spin diode is electrically connected to a first end of the first control wire of the second spin diode, and wherein the cathode of the second spin diode is electrically connected to a first end of the second control wire of the first spin diode;
- (b) a first input terminal electrically connected to a first end of the first control wire of the first spin diode for providing a first input current, IA;
- (c) a second input terminal electrically connected to a first end of the second control wire of the second spin diode for providing a second input current, IB;
- (d) a voltage supply electrically connected to the anodes of the first and second spin diodes for providing a supply voltage, VDD;
- and
- (e) a first output terminal electrically connected to a second end of the first control wire of the second spin diode for outputting a logic “0” or “1” responsive to the first input current IA and the second input current IB.
7 more elements
Dependencies are inferred from the claim text.