Patents by Inventor Linh M. Pham
Linh M. Pham has filed for patents to protect the following inventions. This listing includes patent applications that are pending as well as patents that have already been granted by the United States Patent and Trademark Office (USPTO).
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Patent number: 11346904Abstract: A magnetometer containing a crystal sensor with solid-state defects senses the magnitude and direction of a magnetic field. The solid-state defects in the crystal sensor absorb microwave and optical energy to transition between several energy states while emitting light intensity indicative of their spin states. The magnetic field alters the spin-state transitions of the solid-state defects by amounts depending on the solid-state defects' orientations with respect to the magnetic field. The optical read out, reporting the spin state of an ensemble of solid-state defects from one particular orientation class, can be used to lock microwave signals to the resonances associated with the spin-state transitions. The frequencies of the locked microwave signals can be used to reconstruct the magnetic field vector.Type: GrantFiled: July 6, 2020Date of Patent: May 31, 2022Assignee: Massachusetts Institute of TechnologyInventors: Linh M. Pham, Kerry Alexander Johnson, Carson Arthur Teale, Hannah A. Clevenson, Danielle Ann Braje, Christopher Michael McNally, John Francis Barry
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Publication number: 20210263117Abstract: We have developed a high-performance, low-volume, low-weight, and low-power sensor based on a self-sustaining oscillator. The techniques described here may be used for sensing various fields; we demonstrate magnetic sensing. The oscillator is based on a dielectric resonator that contains paramagnetic defects and is connected to a sustaining amplifier in a feedback loop. The resonance frequency of the dielectric resonator shifts in response to changes in the magnetic field, resulting in a shift in the frequency of the self-sustaining oscillator. The value of the magnetic field is thereby encoded in the shift or modulation output of the self-sustaining oscillator. The sensor as demonstrated uses no optics, no input microwaves, and, not including digitization electronics, consumes less than 300 mW of power and exhibits a sensitivity at or below tens of pT/?{square root over (Hz)}. In some implementations, the sensor is less than 1 mL in volume.Type: ApplicationFiled: December 28, 2020Publication date: August 26, 2021Inventors: Danielle A. Braje, Jennifer Schloss, Linh M. Pham, John F. Barry, Erik R. Eisenach, Michael F. O'Keeffe, Jonah A. Majumder, Jessica Kedziora, Peter Moulton, Matthew Steinecker
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Publication number: 20210255258Abstract: Microwave resonator readout of the cavity-spin interaction between a spin defect center ensemble and a microwave resonator yields fidelities that are orders of magnitude higher than is possible with optical readouts. In microwave resonator readout, microwave photons probe a microwave resonator coupled to a spin defect center ensemble subjected to a physical parameter to be measured. The physical parameter shifts the spin defect centers' resonances, which in turn change the dispersion and/or absorption of the microwave resonator. The microwave photons probe these dispersion and/or absorption changes, yielding a measurement with higher visibility, lower shot noise, better sensitivity, and higher signal-to-noise ratio than a comparable fluorescence measurement. In addition, microwave resonator readout enables coherent averaging of spin defect center ensembles and is compatible with spin systems other than nitrogen vacancies in diamond.Type: ApplicationFiled: March 1, 2021Publication date: August 19, 2021Inventors: John F. Barry, Erik R. Eisenach, Michael F. O'Keeffe, Jonah A. Majumder, Linh M. Pham, Isaac Chuang, Erik M. Thompson, Christopher Louis Panuski, Xingyu Zhang, Danielle A. Braje
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Patent number: 11041916Abstract: Applying a bias magnetic field to a solid-state spin sensor enables vector magnetic field measurements with the solid-state spin sensor. Unfortunately, if the bias magnetic field drifts slowly, it creates noise that confounds low-frequency field measurements. Fortunately, the undesired slow drift of the magnitude of the bias magnetic field can be removed, nullified, or cancelled by reversing the direction (polarity) of the bias magnetic field at known intervals. This makes the resulting solid-state spin sensor system suitable for detecting low-frequency (mHz, for example) changes in magnetic field or other physical parameters.Type: GrantFiled: August 21, 2018Date of Patent: June 22, 2021Assignee: Massachusetts Institute of TechnologyInventors: Linh M. Pham, Erik M. Thompson, John F. Barry, Kerry A. Johnson, Danielle A. Braje
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Patent number: 10962611Abstract: Microwave resonator readout of the cavity-spin interaction between a spin defect center ensemble and a microwave resonator yields fidelities that are orders of magnitude higher than is possible with optical readouts. In microwave resonator readout, microwave photons probe a microwave resonator coupled to a spin defect center ensemble subjected to a physical parameter to be measured. The physical parameter shifts the spin defect centers' resonances, which in turn change the dispersion and/or absorption of the microwave resonator. The microwave photons probe these dispersion and/or absorption changes, yielding a measurement with higher visibility, lower shot noise, better sensitivity, and higher signal-to-noise ratio than a comparable fluorescence measurement. In addition, microwave resonator readout enables coherent averaging of spin defect center ensembles and is compatible with spin systems other than nitrogen vacancies in diamond.Type: GrantFiled: August 27, 2019Date of Patent: March 30, 2021Assignee: Massachusetts Institute of TechnologyInventors: John F. Barry, Erik R. Eisenach, Michael F. O'Keeffe, Jonah A. Majumder, Linh M. Pham, Isaac Chuang, Erik M. Thompson, Christopher Louis Panuski, Xingyu Zhang, Danielle A. Braje
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Publication number: 20210011098Abstract: A magnetometer containing a crystal sensor with solid-state defects senses the magnitude and direction of a magnetic field. The solid-state defects in the crystal sensor absorb microwave and optical energy to transition between several energy states while emitting light intensity indicative of their spin states. The magnetic field alters the spin-state transitions of the solid-state defects by amounts depending on the solid-state defects' orientations with respect to the magnetic field. The optical read out, reporting the spin state of an ensemble of solid-state defects from one particular orientation class, can be used to lock microwave signals to the resonances associated with the spin-state transitions. The frequencies of the locked microwave signals can be used to reconstruct the magnetic field vector.Type: ApplicationFiled: July 6, 2020Publication date: January 14, 2021Inventors: Linh M. Pham, Kerry Alexander Johnson, Carson Arthur TEALE, Hannah A. CLEVENSON, Danielle Ann Braje, Christopher Michael MCNALLY, John Francis BARRY
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Patent number: 10712408Abstract: A magnetometer containing a crystal sensor with solid-state defects senses the magnitude and direction of a magnetic field. The solid-state defects in the crystal sensor absorb microwave and optical energy to transition between several energy states while emitting light intensity indicative of their spin states. The magnetic field alters the spin-state transitions of the solid-state defects by amounts depending on the solid-state defects' orientations with respect to the magnetic field. The optical read out, reporting the spin state of an ensemble of solid-state defects from one particular orientation class, can be used to lock microwave signals to the resonances associated with the spin-state transitions. The frequencies of the locked microwave signals can be used to reconstruct the magnetic field vector.Type: GrantFiled: November 8, 2017Date of Patent: July 14, 2020Assignee: Massachusetts Institute of TechnologyInventors: Linh M. Pham, Carson Arthur Teale, Hannah A. Clevenson, Kerry Alexander Johnson, Christopher Michael McNally, John Francis Barry, Danielle Ann Braje
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Patent number: 10705163Abstract: Here we present a solid-state spin sensor with enhanced sensitivity. The enhanced sensitivity is achieved by increasing the T2* dephasing time of the color center defects within the solid-state spin sensor. The T2* dephasing time extension is achieved by mitigating dipolar coupling between paramagnetic defects within the solid-state spin sensor. The mitigation of the dipolar coupling is achieved by applying a magic-angle-spinning magnetic field to the color center defects. This field is generated by driving a magnetic field generator (e.g., Helmholtz coils) with phase-shifted sinusoidal waveforms from current source impedance-matched to the magnetic field generator. The waveforms may oscillate (and the field may rotate) at a frequency based on the precession period of the color center defects to reduce color center defect dephasing and further enhance measurement sensitivity.Type: GrantFiled: November 29, 2018Date of Patent: July 7, 2020Assignee: Massachusetts Institute of TechnologyInventors: John F. Barry, Danielle A. Braje, Erik R. Eisenach, Christopher Michael McNally, Michael F. O'Keeffe, Linh M. Pham
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Publication number: 20200064419Abstract: Microwave resonator readout of the cavity-spin interaction between a spin defect center ensemble and a microwave resonator yields fidelities that are orders of magnitude higher than is possible with optical readouts. In microwave resonator readout, microwave photons probe a microwave resonator coupled to a spin defect center ensemble subjected to a physical parameter to be measured. The physical parameter shifts the spin defect centers' resonances, which in turn change the dispersion and/or absorption of the microwave resonator. The microwave photons probe these dispersion and/or absorption changes, yielding a measurement with higher visibility, lower shot noise, better sensitivity, and higher signal-to-noise ratio than a comparable fluorescence measurement. In addition, microwave resonator readout enables coherent averaging of spin defect center ensembles and is compatible with spin systems other than nitrogen vacancies in diamond.Type: ApplicationFiled: August 27, 2019Publication date: February 27, 2020Inventors: John F. Barry, Erik R. Eisenach, Michael F. O'Keeffe, Jonah A. Majumder, Linh M. Pham, Isaac Chuang, Erik M. Thompson, Christopher Louis Panuski, Xingyu Zhang, Danielle A. Braje
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Publication number: 20200025835Abstract: Applying a bias magnetic field to a solid-state spin sensor enables vector magnetic field measurements with the solid-state spin sensor. Unfortunately, if the bias magnetic field drifts slowly, it creates noise that confounds low-frequency field measurements. Fortunately, the undesired slow drift of the magnitude of the bias magnetic field can be removed, nullified, or cancelled by reversing the direction (polarity) of the bias magnetic field at known intervals. This makes the resulting solid-state spin sensor system suitable for detecting low-frequency (mHz, for example) changes in magnetic field or other physical parameters.Type: ApplicationFiled: August 21, 2018Publication date: January 23, 2020Inventors: Linh M. Pham, Erik M. Thompson, John F. Barry, Kerry A. Johnson, Danielle A. Braje
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Publication number: 20190178958Abstract: Here we present a solid-state spin sensor with enhanced sensitivity. The enhanced sensitivity is achieved by increasing the T2* dephasing time of the color center defects within the solid-state spin sensor. The T2* dephasing time extension is achieved by mitigating dipolar coupling between paramagnetic defects within the solid-state spin sensor. The mitigation of the dipolar coupling is achieved by applying a magic-angle-spinning magnetic field to the color center defects. This field is generated by driving a magnetic field generator (e.g., Helmholtz coils) with phase-shifted sinusoidal waveforms from current source impedance-matched to the magnetic field generator. The waveforms may oscillate (and the field may rotate) at a frequency based on the precession period of the color center defects to reduce color center defect dephasing and further enhance measurement sensitivity.Type: ApplicationFiled: November 29, 2018Publication date: June 13, 2019Inventors: John F. Barry, Danielle A. Braje, Erik R. Eisenach, Christopher Michael McNally, Michael F. O'Keeffe, Linh M. Pham
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Publication number: 20180136291Abstract: A magnetometer containing a crystal sensor with solid-state defects senses the magnitude and direction of a magnetic field. The solid-state defects in the crystal sensor absorb microwave and optical energy to transition between several energy states while emitting light intensity indicative of their spin states. The magnetic field alters the spin-state transitions of the solid-state defects by amounts depending on the solid-state defects' orientations with respect to the magnetic field. The optical read out, reporting the spin state of an ensemble of solid-state defects from one particular orientation class, can be used to lock microwave signals to the resonances associated with the spin-state transitions. The frequencies of the locked microwave signals can be used to reconstruct the magnetic field vector.Type: ApplicationFiled: November 8, 2017Publication date: May 17, 2018Inventors: Linh M. Pham, Kerry Alexander Johnson, Carson Arthur Teale, Hannah A. Clevenson, Danielle Ann Braje, Christopher Michael McNally, John Francis Barry