Research Topics - Revision history

Mahnsoo.Choi at 07:52, 17 September 2023

2023-09-17T07:52:44Z

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	Despite the considerable efforts ever since the discovery of the high-temperature cuprates, the superconducting mechanism still remains unclear. Based on the symmetries inherited from the system, however, the phenomenological descriptions in terms of the Ginzburg-Landau theory for the superconducting order parameter have achieved great success. The phase-sensitive experiments to determine the symmetry of the superconducting pairing state demonstrates one of such success. Covering various unconventional superconductors, independently of the microscopic mechanism behind the superconductivity, such a description has been applied to problems of unconventional Josephson effects, vortex structures, and magnetic properties. In my work on two coupled order parameters, I studied the vortex structures and corresponding magnetizations in d-wave superconductors. The critical behavior of such a phenomenological model, especially in highly-layered superconductors, is also of much interest.		Despite the considerable efforts ever since the discovery of the high-temperature cuprates, the superconducting mechanism still remains unclear. Based on the symmetries inherited from the system, however, the phenomenological descriptions in terms of the Ginzburg-Landau theory for the superconducting order parameter have achieved great success. The phase-sensitive experiments to determine the symmetry of the superconducting pairing state demonstrates one of such success. Covering various unconventional superconductors, independently of the microscopic mechanism behind the superconductivity, such a description has been applied to problems of unconventional Josephson effects, vortex structures, and magnetic properties. In my work on two coupled order parameters, I studied the vortex structures and corresponding magnetizations in d-wave superconductors. The critical behavior of such a phenomenological model, especially in highly-layered superconductors, is also of much interest.

			[[Category:Default]]

Mahnsoo.Choi at 07:31, 21 September 2018

2018-09-21T07:31:29Z

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	<li>Spin Transport and Quantum Information Processing with Spins.</li>		<li>Spin Transport and Quantum Information Processing with Spins.</li>
	</ul>		</ul>

	~~{{Warning\|...}}~~

	<div style="margin:1em;padding:1ex;border-style:solid;border-width:1px;max-width:20em;float:right;">__TOC__</div>		<div style="margin:1em;padding:1ex;border-style:solid;border-width:1px;max-width:20em;float:right;">__TOC__</div>

Mahnsoo.Choi at 07:30, 21 September 2018

2018-09-21T07:30:55Z

← Older revision		Revision as of 07:30, 21 September 2018
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	<li>Spin Transport and Quantum Information Processing with Spins.</li>		<li>Spin Transport and Quantum Information Processing with Spins.</li>
	</ul>		</ul>

			{{Warning\|...}}

	<div style="margin:1em;padding:1ex;border-style:solid;border-width:1px;max-width:20em;float:right;">__TOC__</div>		<div style="margin:1em;padding:1ex;border-style:solid;border-width:1px;max-width:20em;float:right;">__TOC__</div>

Mahnsoo.Choi at 11:05, 19 July 2016

2016-07-19T11:05:00Z

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	~~[[Testing Smurf]]~~
	<p>		<p>
	We seek physical principles and methods for coherent manipulation of quantum states of mesoscopic systems, and study<br/>		We seek physical principles and methods for coherent manipulation of quantum states of mesoscopic systems, and study<br/>

Mahnsoo.Choi at 11:04, 19 July 2016

2016-07-19T11:04:15Z

← Older revision		Revision as of 11:04, 19 July 2016
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			[[Testing Smurf]]
	<p>		<p>
	We seek physical principles and methods for coherent manipulation of quantum states of mesoscopic systems, and study<br/>		We seek physical principles and methods for coherent manipulation of quantum states of mesoscopic systems, and study<br/>

Mahnsoo.Choi: Changed protection level for "Research Topics" ([Edit=] (indefinite) [Move=] (indefinite))

2016-07-08T12:29:22Z

Changed protection level for "Research Topics" ([Edit=<protect-level-committee>] (indefinite) [Move=<protect-level-committee>] (indefinite))

← Older revision		Revision as of 12:29, 8 July 2016
(No difference)

Mahnsoo.Choi: /* Not Just Violation, But Violation with Style */

2016-07-08T00:31:38Z

Not Just Violation, But Violation with Style

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	* [https://dx.doi.org/10.1038/srep27603 Scientific Reports '''6''', 27603 (2016)]		* [https://dx.doi.org/10.1038/srep27603 Scientific Reports '''6''', 27603 (2016)]

			<div style="max-width:100ex;">
	The Jarzynski equality holds for ridiculously general cases, essentially for any non-equilibrium dynamic processes. Prof. Mahn-Soo Choi and his student Seungju Han in an international collaboration find the violation of the Jarzynski equality over second-order phase transitions, where the violation exhibits a scaling law inherited from the spontaneous symmetry breaking. The rare violation of the Jarzynski equality was pointed out previously for a rather unrealistic or physically uninteresting models, but the present work reveals a universal violation in a wide range of physical models.		The Jarzynski equality holds for ridiculously general cases, essentially for any non-equilibrium dynamic processes. Prof. Mahn-Soo Choi and his student Seungju Han in an international collaboration find the violation of the Jarzynski equality over second-order phase transitions, where the violation exhibits a scaling law inherited from the spontaneous symmetry breaking. The rare violation of the Jarzynski equality was pointed out previously for a rather unrealistic or physically uninteresting models, but the present work reveals a universal violation in a wide range of physical models.
			</div>

	===Prof. Choi Organizes a Special Issue of Physics & High Technology as the Guest Editor===		===Prof. Choi Organizes a Special Issue of Physics & High Technology as the Guest Editor===

Mahnsoo.Choi: /* Prof. Choi Organizes a Special Issue of Physics & High Technology as the Guest Editor */

2016-07-08T00:31:07Z

Prof. Choi Organizes a Special Issue of Physics & High Technology as the Guest Editor

← Older revision		Revision as of 00:31, 8 July 2016
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	* [http://www.kps.or.kr/home/webzine/main.asp Physics & High Technology (May 2016)]		* [http://www.kps.or.kr/home/webzine/main.asp Physics & High Technology (May 2016)]

			<div style="max-width:100ex;">
	After nearly a decade of topological insulators, physicists are now looking into topological semimetals, three dimensional metals with Weyl particles as elementary excitations. Chiral anomaly and surface Fermi arcs are two of many examples of topological features.		After nearly a decade of topological insulators, physicists are now looking into topological semimetals, three dimensional metals with Weyl particles as elementary excitations. Chiral anomaly and surface Fermi arcs are two of many examples of topological features.

	As condensed matter physics falls in love with topology, Prof. Mahn-Soo Choi, as the Guest Editor, has organized a special issue of Physics and High Technology published by the Korea Physical Society. He himself wrote an [http://www.kps.or.kr/storage/webzine_uploadfiles/2634_article.pdf article] in the issue together with his former postdoc Prof. Minchul Lee at Kyunghee University. In 2011, he had written a [http://www.kps.or.kr/storage/webzine_uploadfiles/1530_article.pdf review article] in [http://www.kps.or.kr/home/webzine/main.asp another special issue (on topological insulator)] of the same magazine.		As condensed matter physics falls in love with topology, Prof. Mahn-Soo Choi, as the Guest Editor, has organized a special issue of Physics and High Technology published by the Korea Physical Society. He himself wrote an [http://www.kps.or.kr/storage/webzine_uploadfiles/2634_article.pdf article] in the issue together with his former postdoc Prof. Minchul Lee at Kyunghee University. In 2011, he had written a [http://www.kps.or.kr/storage/webzine_uploadfiles/1530_article.pdf review article] in [http://www.kps.or.kr/home/webzine/main.asp another special issue (on topological insulator)] of the same magazine.
			</div>

	===Stronger Coupling Sets Free Photons Back===		===Stronger Coupling Sets Free Photons Back===

Mahnsoo.Choi: /* Stronger Coupling Sets Free Photons Back */

2016-07-08T00:30:47Z

Stronger Coupling Sets Free Photons Back

← Older revision		Revision as of 00:30, 8 July 2016
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	* [http://dx.doi.org/10.1103/PhysRevLett.116.153601 Physical Review Letter '''116''', 153601 (2016)]		* [http://dx.doi.org/10.1103/PhysRevLett.116.153601 Physical Review Letter '''116''', 153601 (2016)]

			<div style="max-width:100ex;">
	Just like photons mediate the interaction between charged particles, qubits do so among photons. The qubit-mediated force is repulsive and has been known to cause the photon blockade effect. Prof. Mahn-Soo Choi in collaboration with his former student Dr. Myung-Joong Hwang at Univ of Ulm, Germany and Prof. Myungshik Kim at Imperial College London reveals in a recent Physical Review Letter article that as the photon-qubit coupling gets even stronger, the interaction decreases back and photons get free of it.		Just like photons mediate the interaction between charged particles, qubits do so among photons. The qubit-mediated force is repulsive and has been known to cause the photon blockade effect. Prof. Mahn-Soo Choi in collaboration with his former student Dr. Myung-Joong Hwang at Univ of Ulm, Germany and Prof. Myungshik Kim at Imperial College London reveals in a recent Physical Review Letter article that as the photon-qubit coupling gets even stronger, the interaction decreases back and photons get free of it.
			</div>

	===Negative Tunneling Magneto-Resistance (TMR) in LAO/STO===		===Negative Tunneling Magneto-Resistance (TMR) in LAO/STO===

Mahnsoo.Choi: /* Prof. Choi Organizes a Special Issue of Physics & High Technology as the Guest Editor */

2016-07-08T00:30:07Z

Prof. Choi Organizes a Special Issue of Physics & High Technology as the Guest Editor

← Older revision		Revision as of 00:30, 8 July 2016
Line 29:		Line 29:
	After nearly a decade of topological insulators, physicists are now looking into topological semimetals, three dimensional metals with Weyl particles as elementary excitations. Chiral anomaly and surface Fermi arcs are two of many examples of topological features.		After nearly a decade of topological insulators, physicists are now looking into topological semimetals, three dimensional metals with Weyl particles as elementary excitations. Chiral anomaly and surface Fermi arcs are two of many examples of topological features.

	As condensed matter physics falls in love with topology, Prof. Mahn-Soo Choi, as the Guest Editor, has organized a special issue of Physics and High Technology published by the Korea Physical Society. He himself wrote an article in the issue together with his former postdoc Prof. Minchul Lee at Kyunghee University. In 2011, he had written a [http://www.kps.or.kr/storage/webzine_uploadfiles/1530_article.pdf review article] in [http://www.kps.or.kr/home/webzine/main.asp another special issue (on topological insulator)] of the same magazine.		As condensed matter physics falls in love with topology, Prof. Mahn-Soo Choi, as the Guest Editor, has organized a special issue of Physics and High Technology published by the Korea Physical Society. He himself wrote an [http://www.kps.or.kr/storage/webzine_uploadfiles/2634_article.pdf article] in the issue together with his former postdoc Prof. Minchul Lee at Kyunghee University. In 2011, he had written a [http://www.kps.or.kr/storage/webzine_uploadfiles/1530_article.pdf review article] in [http://www.kps.or.kr/home/webzine/main.asp another special issue (on topological insulator)] of the same magazine.

	===Stronger Coupling Sets Free Photons Back===		===Stronger Coupling Sets Free Photons Back===