Hwang, Myung-Joong - Revision history

Mahnsoo.Choi at 00:42, 12 August 2026

2026-08-12T00:42:06Z

← Older revision		Revision as of 00:42, 12 August 2026
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	Abstract: Nonreciprocal interactions create conflicting dynamical objectives that cannot be simultaneously satisfied, leading to nonreciprocal frustration. Geometric frustration, on the other hand, arises when conflicting static objectives in energy minimization cannot be satisfied. In this work, we show that nonreciprocal interaction among three collective quantum spins, mediated by a damped cavity, induces not only nonreciprocal frustration, intrinsic to nonreciprocity, but also geometric frustration with a remarkable robustness against disorder. It therefore ensures that the accidental degeneracy for steady states remains intact even when the system is perturbed away from a fine-tuned point of enhanced symmetry, in sharp contrast to the equilibrium case. Leveraging this finding, we identify a nonreciprocal phase transition driven by both geometric and nonreciprocal frustration. It gives rise to a time-dependent state, which shows chiral dynamics along a geometry shaped by the geometric frustration and dynamically restores the broken discrete symmetries. Moreover, it constitutes a time-crystalline order, with multiple harmonics set by an emergent time scale that exhibits critical slowing down. We discuss the potential experimental realizations using a three-component spinor BEC-cavity system, where our finding manifests as a geometric frustration in the structural phase transition and chiral dynamics of the frustrated self-organized BECs. We demonstrate the feasibility of experimental observation under realistic conditions.		Abstract: Nonreciprocal interactions create conflicting dynamical objectives that cannot be simultaneously satisfied, leading to nonreciprocal frustration. Geometric frustration, on the other hand, arises when conflicting static objectives in energy minimization cannot be satisfied. In this work, we show that nonreciprocal interaction among three collective quantum spins, mediated by a damped cavity, induces not only nonreciprocal frustration, intrinsic to nonreciprocity, but also geometric frustration with a remarkable robustness against disorder. It therefore ensures that the accidental degeneracy for steady states remains intact even when the system is perturbed away from a fine-tuned point of enhanced symmetry, in sharp contrast to the equilibrium case. Leveraging this finding, we identify a nonreciprocal phase transition driven by both geometric and nonreciprocal frustration. It gives rise to a time-dependent state, which shows chiral dynamics along a geometry shaped by the geometric frustration and dynamically restores the broken discrete symmetries. Moreover, it constitutes a time-crystalline order, with multiple harmonics set by an emergent time scale that exhibits critical slowing down. We discuss the potential experimental realizations using a three-component spinor BEC-cavity system, where our finding manifests as a geometric frustration in the structural phase transition and chiral dynamics of the frustrated self-organized BECs. We demonstrate the feasibility of experimental observation under realistic conditions.

			[[Category: Quantum Technology Workshop 2026]]


	==Other Contributions==		==Other Contributions==

Mahnsoo.Choi: /* Nonreciprocal and Geometric Frustration in Dissipative Quantum Spins */

2026-08-10T18:05:08Z

Nonreciprocal and Geometric Frustration in Dissipative Quantum Spins

← Older revision		Revision as of 18:05, 10 August 2026
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	Abstract: Nonreciprocal interactions create conflicting dynamical objectives that cannot be simultaneously satisfied, leading to nonreciprocal frustration. Geometric frustration, on the other hand, arises when conflicting static objectives in energy minimization cannot be satisfied. In this work, we show that nonreciprocal interaction among three collective quantum spins, mediated by a damped cavity, induces not only nonreciprocal frustration, intrinsic to nonreciprocity, but also geometric frustration with a remarkable robustness against disorder. It therefore ensures that the accidental degeneracy for steady states remains intact even when the system is perturbed away from a fine-tuned point of enhanced symmetry, in sharp contrast to the equilibrium case. Leveraging this finding, we identify a nonreciprocal phase transition driven by both geometric and nonreciprocal frustration. It gives rise to a time-dependent state, which shows chiral dynamics along a geometry shaped by the geometric frustration and dynamically restores the broken discrete symmetries. Moreover, it constitutes a time-crystalline order, with multiple harmonics set by an emergent time scale that exhibits critical slowing down. We discuss the potential experimental realizations using a three-component spinor BEC-cavity system, where our finding manifests as a geometric frustration in the structural phase transition and chiral dynamics of the frustrated self-organized BECs. We demonstrate the feasibility of experimental observation under realistic conditions.		Abstract: Nonreciprocal interactions create conflicting dynamical objectives that cannot be simultaneously satisfied, leading to nonreciprocal frustration. Geometric frustration, on the other hand, arises when conflicting static objectives in energy minimization cannot be satisfied. In this work, we show that nonreciprocal interaction among three collective quantum spins, mediated by a damped cavity, induces not only nonreciprocal frustration, intrinsic to nonreciprocity, but also geometric frustration with a remarkable robustness against disorder. It therefore ensures that the accidental degeneracy for steady states remains intact even when the system is perturbed away from a fine-tuned point of enhanced symmetry, in sharp contrast to the equilibrium case. Leveraging this finding, we identify a nonreciprocal phase transition driven by both geometric and nonreciprocal frustration. It gives rise to a time-dependent state, which shows chiral dynamics along a geometry shaped by the geometric frustration and dynamically restores the broken discrete symmetries. Moreover, it constitutes a time-crystalline order, with multiple harmonics set by an emergent time scale that exhibits critical slowing down. We discuss the potential experimental realizations using a three-component spinor BEC-cavity system, where our finding manifests as a geometric frustration in the structural phase transition and chiral dynamics of the frustrated self-organized BECs. We demonstrate the feasibility of experimental observation under realistic conditions.


	==Other Contributions==		==Other Contributions==

Mahnsoo.Choi at 18:04, 10 August 2026

2026-08-10T18:04:48Z

← Older revision		Revision as of 18:04, 10 August 2026
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	Myung-Joong Hwang is an Associate Professor of Physics at Duke Kunshan University in China and an Associate Professor of Practice at Duke University in U.S. His research focuses on uncovering novel quantum phenomena and designing controlled quantum systems based on superconducting circuits and AMO systems such as ion-traps and cold atoms with optical cavities and harnessing them for quantum computing and quantum sensing. He has a Ph.D in physics from Pohang University of Science and Technology, South Korea. Before joining Duke Kunshan, he was a postdoctoral researcher at the Institute of Theoretical Physics at Ulm University, Germany.		Myung-Joong Hwang is an Associate Professor of Physics at Duke Kunshan University in China and an Associate Professor of Practice at Duke University in U.S. His research focuses on uncovering novel quantum phenomena and designing controlled quantum systems based on superconducting circuits and AMO systems such as ion-traps and cold atoms with optical cavities and harnessing them for quantum computing and quantum sensing. He has a Ph.D in physics from Pohang University of Science and Technology, South Korea. Before joining Duke Kunshan, he was a postdoctoral researcher at the Institute of Theoretical Physics at Ulm University, Germany.

	==Contributions==		==Nonreciprocal and Geometric Frustration in Dissipative Quantum Spins==

			* Speaker: [[Hwang, Myung-Joong\|Myung-Joong Hwang]] (Duke Kunshan University, China)
			* Event: [[Quantum Technology Workshop 2026]]

			Abstract: Nonreciprocal interactions create conflicting dynamical objectives that cannot be simultaneously satisfied, leading to nonreciprocal frustration. Geometric frustration, on the other hand, arises when conflicting static objectives in energy minimization cannot be satisfied. In this work, we show that nonreciprocal interaction among three collective quantum spins, mediated by a damped cavity, induces not only nonreciprocal frustration, intrinsic to nonreciprocity, but also geometric frustration with a remarkable robustness against disorder. It therefore ensures that the accidental degeneracy for steady states remains intact even when the system is perturbed away from a fine-tuned point of enhanced symmetry, in sharp contrast to the equilibrium case. Leveraging this finding, we identify a nonreciprocal phase transition driven by both geometric and nonreciprocal frustration. It gives rise to a time-dependent state, which shows chiral dynamics along a geometry shaped by the geometric frustration and dynamically restores the broken discrete symmetries. Moreover, it constitutes a time-crystalline order, with multiple harmonics set by an emergent time scale that exhibits critical slowing down. We discuss the potential experimental realizations using a three-component spinor BEC-cavity system, where our finding manifests as a geometric frustration in the structural phase transition and chiral dynamics of the frustrated self-organized BECs. We demonstrate the feasibility of experimental observation under realistic conditions.


			==Other Contributions==
	* [[Quantum phase transition and universal dynamics in the Rabi model]]		* [[Quantum phase transition and universal dynamics in the Rabi model]]

	[[Category:Speakers]]		[[Category:Speakers]]
	[[Category:Old Members]]		[[Category:Old Members]]

Mahnsoo.Choi at 06:16, 30 May 2026

2026-05-30T06:16:50Z

← Older revision		Revision as of 06:16, 30 May 2026
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	~~[[Category:Speakers]]~~		Myung-Joong Hwang is an Associate Professor of Physics at Duke Kunshan University in China and an Associate Professor of Practice at Duke University in U.S. His research focuses on uncovering novel quantum phenomena and designing controlled quantum systems based on superconducting circuits and AMO systems such as ion-traps and cold atoms with optical cavities and harnessing them for quantum computing and quantum sensing. He has a Ph.D in physics from Pohang University of Science and Technology, South Korea. Before joining Duke Kunshan, he was a postdoctoral researcher at the Institute of Theoretical Physics at Ulm University, Germany.
	~~[[Category:Old Members]]~~
	* Postdoctoral Researcher at ~~the [http://qubit~~-~~ulm~~.~~com~~ University of ~~Ulm~~, ~~Germany]~~.
	* PhD from POSTECH in 2014.

	~~As of June 27, 2019~~, he ~~is now moving to [https://dukekunshan.edu.cn/en Duke Kushan University] in China to join~~ the ~~Faculty~~ of Physics ~~Department~~.

	==Contributions==		==Contributions==
	* [[Quantum phase transition and universal dynamics in the Rabi model]]		* [[Quantum phase transition and universal dynamics in the Rabi model]]

			[[Category:Speakers]]
			[[Category:Old Members]]

Mahnsoo.Choi: Changed protection level for "Hwang, Myung-Joong" ([Edit=⧼protect-level-board⧽] (indefinite) [Move=⧼protect-level-board⧽] (indefinite))

2021-01-01T23:22:51Z

Changed protection level for "Hwang, Myung-Joong" ([Edit=⧼protect-level-board⧽] (indefinite) [Move=⧼protect-level-board⧽] (indefinite))

← Older revision	Revision as of 23:22, 1 January 2021
(No difference)

Mahnsoo.Choi at 08:46, 27 June 2019

2019-06-27T08:46:09Z

← Older revision		Revision as of 08:46, 27 June 2019
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	* PhD from POSTECH in 2014.		* PhD from POSTECH in 2014.

	As of June 27, 2019, he is now moving to Duke Kushan University in China to join the Faculty of Physics Department.		As of June 27, 2019, he is now moving to [https://dukekunshan.edu.cn/en Duke Kushan University] in China to join the Faculty of Physics Department.

	==Contributions==		==Contributions==
	* [[Quantum phase transition and universal dynamics in the Rabi model]]		* [[Quantum phase transition and universal dynamics in the Rabi model]]

Mahnsoo.Choi at 08:45, 27 June 2019

2019-06-27T08:45:27Z

← Older revision		Revision as of 08:45, 27 June 2019
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	* PhD from POSTECH in 2014.		* PhD from POSTECH in 2014.

	He is now moving to Duke Kushan University in China.		As of June 27, 2019, he is now moving to Duke Kushan University in China to join the Faculty of Physics Department.

	==Contributions==		==Contributions==
	* [[Quantum phase transition and universal dynamics in the Rabi model]]		* [[Quantum phase transition and universal dynamics in the Rabi model]]

Mahnsoo.Choi at 08:44, 27 June 2019

2019-06-27T08:44:51Z

← Older revision		Revision as of 08:44, 27 June 2019
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	* Postdoctoral Researcher at the [http://qubit-ulm.com University of Ulm, Germany].		* Postdoctoral Researcher at the [http://qubit-ulm.com University of Ulm, Germany].
	* PhD from POSTECH in 2014.		* PhD from POSTECH in 2014.

			He is now moving to Duke Kushan University in China.

	==Contributions==		==Contributions==
	* [[Quantum phase transition and universal dynamics in the Rabi model]]		* [[Quantum phase transition and universal dynamics in the Rabi model]]

Mahnsoo.Choi at 03:37, 19 July 2016

2016-07-19T03:37:37Z

← Older revision		Revision as of 03:37, 19 July 2016
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	[[Category:Speakers]]		[[Category:Speakers]]
			[[Category:Old Members]]
	* Postdoctoral Researcher at the [http://qubit-ulm.com University of Ulm, Germany].		* Postdoctoral Researcher at the [http://qubit-ulm.com University of Ulm, Germany].
	* PhD from POSTECH in 2014.		* PhD from POSTECH in 2014.

Jhgang at 06:30, 3 February 2016

2016-02-03T06:30:57Z

← Older revision		Revision as of 06:30, 3 February 2016
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	==Contributions==		==Contributions==
			* [[Quantum phase transition and universal dynamics in the Rabi model]]