Cryogenic solid state heat pump
AssigneeNorthwestern University
InventorMatthew Grayson
Life of this patent
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Abstract
Systems and/or methods can provide for solid-state refrigeration below 1 degree Kelvin. By applying a simple sequence of ac electrical signals to a gated semiconductor device, electrons are cooled in a refrigeration sequence that, in turn, provides cooling directly to the heat load of interest. Electrons in a single subband of a semiconductor quantum well are expanded adiabatically into several subbands, resulting in a temperature drop. Repeated application of this cycle at MHz-GHz frequencies results in a significant cooling power. The anticipated cooling powers can compete with today's standard cryogenic system, the dilution refrigerator, which represents the market standard for achieving cryogenic temperatures.
Claims20
A device, comprising:
- a central reservoir configured to isolate electrons;
- a first reservoir in communication with the central reservoir;
- and
- a second reservoir in communication with the central reservoir, wherein the electrons are isolated in the central reservoir and expanded from a single subband state into a multi-subband state when the device is selectively operated at a first stage, wherein heat from the first reservoir is exchanged with the central reservoir when the device operates a second stage responsive to the device operating at the first stage, wherein the electrons are isolated and compressed in the central reservoir from the multi-subband state to the single subband state when the device is selectively operated at a third stage subsequent to the heat being exchanged between the first reservoir and the central reservoir, and wherein excess heat in the central reservoir generated during the second stage is ejected into the second reservoir when the device operates at a fourth stage responsive to the device operating at the third stage.
A method, comprising:
- selectively operating a device at a first stage to isolate electrons in a central reservoir and expand the electrons from a single subband state into a multi-subband state, wherein the central reservoir is in communication with a first reservoir;
- exchanging heat from the first reservoir to the central reservoir when the device operates at a second stage responsive to the device operating at the first stage;
- selectively operating the device at a third stage, subsequent to the second stage, to isolate the electrons in the central reservoir and compress the electrons in the central reservoir from the multi-subband state to the single subband state, wherein the central reservoir is in communication with a second reservoir;
- and
- ejecting excess heat in the central reservoir, generated during the third stage, into the second reservoir when the device operates at a fourth stage responsive to the device operating at the third stage.
A device, comprising:
- a central reservoir configured to isolate electrons;
- a first reservoir in communication with the central reservoir;
- and
- a second reservoir in communication with the central reservoir, wherein the electrons are isolated in the central reservoir and expanded from a single-valley state into a triple-valley state when the device is selectively operated at a first stage, wherein heat from the first reservoir is exchanged with the central reservoir when the device operates a second stage responsive to the device operating at the first stage, wherein the electrons are isolated and compressed in the central reservoir from the triple-valley state to the single valley state when the device is selectively operated at a third stage subsequent to the heat being exchanged between the first reservoir and the central reservoir, and wherein excess heat in the central reservoir generated during the second stage is ejected into the second reservoir when the device operates at a fourth stage responsive to the device operating at the third stage.
Dependencies are inferred from the claim text.