QCLab - User contributions [en]

임현식

2016-03-07T11:29:27Z

Jhgang: Redirected page to Im, Hyunsik

#redirect [[Im, Hyunsik]]
[[Category: Speakers]]
[[Category: Condensed Matter Speakers]]

구현철

2016-03-07T11:26:36Z

Jhgang: Redirected page to Koo, Hyun Cheol

#redirect [[Koo, Hyun Cheol]]
[[Category: Speakers]]
[[Category: Condensed Matter Speakers]]

최석봉

2016-03-07T11:23:55Z

Jhgang: Redirected page to Choe, Sug-Bong

#redirect [[Choe, Sug-Bong]]
[[Category: Speakers]]
[[Category: Condensed Matter Speakers]]

나노구조 자성 동력학 측정

2016-03-07T11:20:04Z

Jhgang:

* Speaker: [[Choe, Sug-Bong|Sug-Bong Choe]] (Seoul National University)
* Date: Wednesday March 16, 2016 17:00
* Place: Asan Science Building, Room 199

정보저장을 위한 자성체 응용분야의 역사와 현황, 그리고 현재의 연구 쟁점을 개략적으로 살펴보고, 이러한 자성체에서 나노구조-나노초 시간대에서 발생하는 자성 동력학을 측정하는 측정기술로서 광자기 현미경, 엑스선 현미경, 전자 현미경 기술의 개발 단계와 현재 진행되고 있는 핵심 연구 주제에 대해 설명합니다. 이러한 측정기술을 바탕으로, 자기소용돌이 구조의 나노미터-피코초 동역학의 관찰[1]과 나노선 소자에서의 차원변환 현상[2]에 대해서 논의합니다.

참고문헌<br />[1] S.-B. Choe et al., Science 304, 420 (2004).<br />[2] K.-J. Kim et al., Nature 458, 740 (2009).

[[Category:Condensed Matter Seminars]]
[[Category:Seminars]]

나노구조 자성 동력학 측정

2016-03-07T11:19:53Z

Jhgang:

* Speaker: [[Choe, Sug-Bong|Sug-Bong Choe]] (Seoul National University)
* Date: Wednesday March 16, 2016 17:00
* Place: Asan Science Building, Room 199

정보저장을 위한 자성체 응용분야의 역사와 현황, 그리고 현재의 연구 쟁점을 개략적으로 살펴보고, 이러한 자성체에서 나노구조-나노초 시간대에서 발생하는 자성 동력학을 측정하는 측정기술로서 광자기 현미경, 엑스선 현미경, 전자 현미경 기술의 개발 단계와 현재 진행되고 있는 핵심 연구 주제에 대해 설명합니다. 이러한 측정기술을 바탕으로, 자기소용돌이 구조의 나노미터-피코초 동역학의 관찰[1]과 나노선 소자에서의 차원변환 현상[2]에 대해서 논의합니다.

참고문헌

[1] S.-B. Choe et al., Science 304, 420 (2004).<br />[2] K.-J. Kim et al., Nature 458, 740 (2009).

[[Category:Condensed Matter Seminars]]
[[Category:Seminars]]

나노구조 자성 동력학 측정

2016-03-07T11:18:49Z

Jhgang:

* Speaker: [[Choe, Sug-Bong|Sug-Bong Choe]] (Seoul National University)
* Date: Wednesday March 16, 2016 17:00
* Place: Asan Science Building, Room 199

정보저장을 위한 자성체 응용분야의 역사와 현황, 그리고 현재의 연구 쟁점을 개략적으로 살펴보고, 이러한 자성체에서 나노구조-나노초 시간대에서 발생하는 자성 동력학을 측정하는 측정기술로서 광자기 현미경, 엑스선 현미경, 전자 현미경 기술의 개발 단계와 현재 진행되고 있는 핵심 연구 주제에 대해 설명합니다. 이러한 측정기술을 바탕으로, 자기소용돌이 구조의 나노미터-피코초 동역학의 관찰[1]과 나노선 소자에서의 차원변환 현상[2]에 대해서 논의합니다.

참고문헌

[1] S.-B. Choe et al., Science 304, 420 (2004).

[2] K.-J. Kim et al., Nature 458, 740 (2009).

[[Category:Condensed Matter Seminars]]
[[Category:Seminars]]

나노구조 자성 동력학 측정

2016-03-07T11:18:39Z

Jhgang:

* Speaker: [[Choe, Sug-Bong|Sug-Bong Choe]] (Seoul National University)
* Date: Wednesday March 16, 2016 17:00
* Place: Asan Science Building, Room 199

정보저장을 위한 자성체 응용분야의 역사와 현황, 그리고 현재의 연구 쟁점을 개략적으로 살펴보고, 이러한 자성체에서 나노구조-나노초 시간대에서 발생하는 자성 동력학을 측정하는 측정기술로서 광자기 현미경, 엑스선 현미경, 전자 현미경 기술의 개발 단계와 현재 진행되고 있는 핵심 연구 주제에 대해 설명합니다. 이러한 측정기술을 바탕으로, 자기소용돌이 구조의 나노미터-피코초 동역학의 관찰[1]과 나노선 소자에서의 차원변환 현상[2]에 대해서 논의합니다.

참고문헌

[1] S.-B. Choe et al., Science 304, 420 (2004).
[2] K.-J. Kim et al., Nature 458, 740 (2009).

[[Category:Condensed Matter Seminars]]
[[Category:Seminars]]

Choe, Sug-Bong

2016-03-07T11:17:43Z

Jhgang:

[[Category:Speakers]]
[[Category:Condensed Matter Speakers]]
* Seoul National University
*Department of Physics & Astronomy

==Contributions==
* [[나노구조 자성 동력학 측정]]

나노구조 자성 동력학 측정

2016-03-07T11:15:45Z

Jhgang:

* Speaker: [[Choe, Sug-Bong|Sug-Bong Choe]] (Seoul National University)
* Date: Wednesday March 16, 2016 17:00
* Place: Asan Science Building, Room 199

정보저장을 위한 자성체 응용분야의 역사와 현황, 그리고 현재의 연구 쟁점을 개략적으로 살펴보고, 이러한 자성체에서 나노구조-나노초 시간대에서 발생하는 자성 동력학을 측정하는 측정기술로서 광자기 현미경, 엑스선 현미경, 전자 현미경 기술의 개발 단계와 현재 진행되고 있는 핵심 연구 주제에 대해 설명합니다. 이러한 측정기술을 바탕으로, 자기소용돌이 구조의 나노미터-피코초 동역학의 관찰[1]과 나노선 소자에서의 차원변환 현상[2]에 대해서 논의합니다.

참고문헌

[1] S.-B. Choe et al., Science 304, 420 (2004).

[2] K.-J. Kim et al., Nature 458, 740 (2009).

[[Category:Condensed Matter Seminars]]
[[Category:Seminars]]

나노구조 자성 동력학 측정

2016-03-07T11:15:15Z

Jhgang:

* Speaker: [[Choe, Sug-Bong|Sug-Bong Choe]] (Seoul National University)
* Date: Wednesday March 16, 2016 17:00
* Place: Asan Science Building, Room 199

정보저장을 위한 자성체 응용분야의 역사와 현황, 그리고 현재의 연구 쟁점을 개략적으로 살펴보고, 이러한 자성체에서 나노구조-나노초 시간대에서 발생하는 자성 동력학을 측정하는 측정기술로서 광자기 현미경, 엑스선 현미경, 전자 현미경 기술의 개발 단계와 현재 진행되고 있는 핵심 연구 주제에 대해 설명합니다. 이러한 측정기술을 바탕으로, 자기소용돌이 구조의 나노미터-피코초 동역학의 관찰[1]과 나노선 소자에서의 차원변환 현상[2]에 대해서 논의합니다.

참고문헌
(1) S.-B. Choe et al., Science 304, 420 (2004).
(2) K.-J. Kim et al., Nature 458, 740 (2009).

[[Category:Condensed Matter Seminars]]
[[Category:Seminars]]

나노구조 자성 동력학 측정

2016-03-07T11:15:06Z

Jhgang:

* Speaker: [[Choe, Sug-Bong|Sug-Bong Choe]] (Seoul National University)
* Date: Wednesday March 16, 2016 17:00
* Place: Asan Science Building, Room 199

정보저장을 위한 자성체 응용분야의 역사와 현황, 그리고 현재의 연구 쟁점을 개략적으로 살펴보고, 이러한 자성체에서 나노구조-나노초 시간대에서 발생하는 자성 동력학을 측정하는 측정기술로서 광자기 현미경, 엑스선 현미경, 전자 현미경 기술의 개발 단계와 현재 진행되고 있는 핵심 연구 주제에 대해 설명합니다. 이러한 측정기술을 바탕으로, 자기소용돌이 구조의 나노미터-피코초 동역학의 관찰[1]과 나노선 소자에서의 차원변환 현상[2]에 대해서 논의합니다.

참고문헌

(1) S.-B. Choe et al., Science 304, 420 (2004).
(2) K.-J. Kim et al., Nature 458, 740 (2009).

[[Category:Condensed Matter Seminars]]
[[Category:Seminars]]

나노구조 자성 동력학 측정

2016-03-07T11:14:54Z

Jhgang:

* Speaker: [[Choe, Sug-Bong|Sug-Bong Choe]] (Seoul National University)
* Date: Wednesday March 16, 2016 17:00
* Place: Asan Science Building, Room 199

정보저장을 위한 자성체 응용분야의 역사와 현황, 그리고 현재의 연구 쟁점을 개략적으로 살펴보고, 이러한 자성체에서 나노구조-나노초 시간대에서 발생하는 자성 동력학을 측정하는 측정기술로서 광자기 현미경, 엑스선 현미경, 전자 현미경 기술의 개발 단계와 현재 진행되고 있는 핵심 연구 주제에 대해 설명합니다. 이러한 측정기술을 바탕으로, 자기소용돌이 구조의 나노미터-피코초 동역학의 관찰[1]과 나노선 소자에서의 차원변환 현상[2]에 대해서 논의합니다.

참고문헌
(1) S.-B. Choe et al., Science 304, 420 (2004).
(2) K.-J. Kim et al., Nature 458, 740 (2009).

[[Category:Condensed Matter Seminars]]
[[Category:Seminars]]

나노구조 자성 동력학 측정

2016-03-07T11:13:42Z

Jhgang: Created page with "* Speaker: Sug-Bong Choe (Seoul National University) * Date: Wednesday March 16, 2016 17:00 * Place: Asan Science Building, Room 199 정보저장을 위..."

* Speaker: [[Choe, Sug-Bong|Sug-Bong Choe]] (Seoul National University)
* Date: Wednesday March 16, 2016 17:00
* Place: Asan Science Building, Room 199

정보저장을 위한 자성체 응용분야의 역사와 현황, 그리고 현재의 연구 쟁점을 개략적으로 살펴보고, 이러한 자성체에서 나노구조-나노초 시간대에서 발생하는 자성 동력학을 측정하는 측정기술로서 광자기 현미경, 엑스선 현미경, 전자 현미경 기술의 개발 단계와 현재 진행되고 있는 핵심 연구 주제에 대해 설명합니다. 이러한 측정기술을 바탕으로, 자기소용돌이 구조의 나노미터-피코초 동역학의 관찰[1]과 나노선 소자에서의 차원변환 현상[2]에 대해서 논의합니다.

참고문헌
[1] S.-B. Choe et al., Science 304, 420 (2004).
[2] K.-J. Kim et al., Nature 458, 740 (2009).

[[Category:Condensed Matter Seminars]]
[[Category:Seminars]]

Choe, Sug-Bong

2016-03-07T11:12:12Z

Jhgang:

[[Category:Speakers]]
[[Category:Condensed Matter Speakers]]
* Seoul University

==Contributions==
* [[나노구조 자성 동력학 측정]]

Doping in semiconductors and new magnetic phase transitions in metallic P-doped Si

2016-03-03T08:28:19Z

Jhgang:

* Speaker: [[Im, Hyunsik|Hyunsik Im]] (Dongguk University)
* Date: Wednesday March 23, 2016 17:00
* Place: Asan Science Center, Room 199

Semiconductors are materials that possess the unique ability to extensively control their electronic nature by adding impurities, and this makes them valuable in applications. How the interplay between disorder and electron-electron interactions affects the electronic phase transition of solids has remained a challenging issue over many years. Here we perform high-precision tunneling DOS spectroscopy measurements in P-doped Si in the quasi-degenerate metallic region. We report on the observation of a new magnetic field-driven phase transition between a magnetic metal and a paramagnetic disordered Fermi liquid.

본 세미나는 도핑 된 반도체 (Si)의 상변화 (phase transition)을 다룬다. 전반부에는 전반적인 Si (P,B)에서의 metal insulator transition에 대해 다루며 후반부는 최근 실험에서 얻은 P 도핑된 metallic Si에서의 tunneling DOS spectra 측정 결과와 물리적인 의미에 대해 발표한다.

Keywords: Disorder, RKKY interaction, Spin density wave (SDW), Tunneling DOS spectroscopy.

[[Category:Condensed Matter Seminars]]
[[Category:Seminars]]

Im, Hyunsik

2016-03-03T08:27:08Z

Jhgang: /* Contributions */

[[Category:Speakers]]
[[Category:Condensed Matter Speakers]]
* Dongguk University

==Contributions==
* [[Doping in semiconductors and new magnetic phase transitions in metallic P-doped Si]]

Doping in semiconductors and new magnetic phase transitions in metallic P-doped Si

2016-03-03T08:26:50Z

Jhgang: Created page with "PlaceHolder"

PlaceHolder

Im, Hyunsik

2016-03-03T08:25:37Z

Jhgang:

[[Category:Speakers]]
[[Category:Condensed Matter Speakers]]
* Dongguk University

==Contributions==
* [[Doping in semiconductors & new magnetic phase transitions in metallic P-doped Si]]

Doping in semiconductors & new magnetic phase transitions in metallic P-doped S

2016-03-03T08:23:35Z

Jhgang: Created page with "* Speaker: Hyun Cheol Koo (KIST) * Date: Wednesday March 9, 2016 17:00 * Place: Asan Science Center, Room 199 Placeholder Category:Condensed Matter Sem..."

* Speaker: [[Koo, Hyun Cheol|Hyun Cheol Koo]] (KIST)
* Date: Wednesday March 9, 2016 17:00
* Place: Asan Science Center, Room 199

Placeholder

[[Category:Condensed Matter Seminars]]
[[Category:Seminars]]

Im, Hyunsik

2016-03-03T08:23:02Z

Jhgang: /* Contributions */

[[Category:Speakers]]
[[Category:Condensed Matter Speakers]]
* Dongguk University

==Contributions==
* [[Doping in semiconductors & new magnetic phase transitions in metallic P-doped S]]

Doping in semiconductors & new magnetic phase transitions in metallic P-doped Si

2016-03-03T08:18:21Z

Jhgang: Created page with "* Speaker: Hyunsik Im (Dongguk University) * Date: Wednesday March 23, 2016 17:00 * Place: Asan Science Center, Room 199 Semiconductors are materials that pos..."

Im, Hyunsik

2016-03-03T08:16:54Z

Jhgang:

[[Category:Speakers]]
[[Category:Condensed Matter Speakers]]
* Dongguk University

==Contributions==
* [[Doping in semiconductors & new magnetic phase transitions in metallic P-doped Si]]

Im, Hyunsik

2016-02-29T08:53:12Z

Jhgang:

[[Category:Speakers]]
[[Category:Condensed Matter Speakers]]
* Dongguk University

Im, Hyunsik

2016-02-29T08:52:48Z

Jhgang: Created page with "Category:Speakers Category:Condensed Matter Speakers * Donnguk University"

[[Category:Speakers]]
[[Category:Condensed Matter Speakers]]
* Donnguk University

Choe, Sug-Bong

2016-02-29T08:47:19Z

Jhgang: Created page with "Category:Speakers Category:Condensed Matter Speakers * Seoul University"

[[Category:Speakers]]
[[Category:Condensed Matter Speakers]]
* Seoul University

Spin Transport in a Semiconductor Channel

2016-02-29T08:33:53Z

Jhgang:

* Speaker: [[Koo, Hyun Cheol|Hyun Cheol Koo]] (KIST)
* Date: Wednesday March 9, 2016 17:00
* Place: Asan Science Center, Room 199

In the field of semiconductor spintronics, coherent spin precession in a Rashba effective magnetic field in the channel of a spin field effect transistor and the spin Hall effect are the two most compelling topics. In this talk, the experimental results of spin injection and gate control of spin precession is presented. The original Datta-Das prediction of a gate voltage controlled conductance oscillation in a spin injected field effect transistor (Spin-FET), caused by coherent spin precession in a Rashba spin-orbit system, is the cornerstone of semiconductor spintronics research. Our result is the first experimental observation and confirmation of the Datta-Das prediction. We also combine spin Hall and Rashba effects to provide two novel results: a direct demonstration of the ballistic spin Hall effect and a new technique for an all-electric measurement of the Datta–Das conductance oscillation.

[[Category:Condensed Matter Seminars]]
[[Category:Seminars]]

Koo, Hyun Cheol

2016-02-25T06:11:29Z

Jhgang:

[[Category:Speakers]]
* Center for Spintronics, Korea Institute of Science and Technology (KIST)

==Contributions==
* [[Spin Transport in a Semiconductor Channel]]

Koo, Hyun Cheol

2016-02-25T06:11:15Z

Jhgang: Created page with "Category:Speakers * Center for Spintronics, Korea Institute of Science and Technology (KIST) ==Contributions== * Spin Transport in a Semiconductor Channell"

[[Category:Speakers]]
* Center for Spintronics, Korea Institute of Science and Technology (KIST)

==Contributions==
* [[Spin Transport in a Semiconductor Channell]]

Spin Transport in a Semiconductor Channel

2016-02-25T06:10:01Z

Jhgang:

* Speaker: [[Koo, Hyun Cheol|Hyun Cheol Koo]] (KIST)
* Date: Wednesday March 9, 2016 17:00
* Place: TBA

In the field of semiconductor spintronics, coherent spin precession in a Rashba effective magnetic field in the channel of a spin field effect transistor and the spin Hall effect are the two most compelling topics. In this talk, the experimental results of spin injection and gate control of spin precession is presented. The original Datta-Das prediction of a gate voltage controlled conductance oscillation in a spin injected field effect transistor (Spin-FET), caused by coherent spin precession in a Rashba spin-orbit system, is the cornerstone of semiconductor spintronics research. Our result is the first experimental observation and confirmation of the Datta-Das prediction. We also combine spin Hall and Rashba effects to provide two novel results: a direct demonstration of the ballistic spin Hall effect and a new technique for an all-electric measurement of the Datta–Das conductance oscillation.

Spin Transport in a Semiconductor Channel

2016-02-25T06:08:27Z

Jhgang: Created page with "In the field of semiconductor spintronics, coherent spin precession in a Rashba effective magnetic field in the channel of a spin field effect transistor and the spin Hall eff..."

In the field of semiconductor spintronics, coherent spin precession in a Rashba effective magnetic field in the channel of a spin field effect transistor and the spin Hall effect are the two most compelling topics. In this talk, the experimental results of spin injection and gate control of spin precession is presented. The original Datta-Das prediction of a gate voltage controlled conductance oscillation in a spin injected field effect transistor (Spin-FET), caused by coherent spin precession in a Rashba spin-orbit system, is the cornerstone of semiconductor spintronics research. Our result is the first experimental observation and confirmation of the Datta-Das prediction. We also combine spin Hall and Rashba effects to provide two novel results: a direct demonstration of the ballistic spin Hall effect and a new technique for an all-electric measurement of the Datta–Das conductance oscillation.

Quantum phase transition and universal dynamics in the Rabi model

2016-02-03T06:32:10Z

Jhgang:

* Speaker: [[Hwang, Myung-Joong|Myung-Joong Hwang]] (Univ of Ulm, Germany)
* Date: Monday February 16, 2016 17:00
* Place: Jeongho Seminar Room

In this talk, I will discuss our recent finding [1] that a two-level system coupled to a single-mode cavity field, described by the Rabi model, undergoes a second order quantum phase transition. Having only two constituent particles, the Rabi model is far from being in a thermodynamic limit; however, out study shows that an infinite ratio of the atomic transition frequency to the cavity frequency can play the role of thermodynamic limit. I first prove the quantum phase transition of the model by developing an effective low-energy theory for the infinite frequency-ratio limit. Then, in the sprit of finite-size scaling theory, I will discuss the influence of the criticality on a finite frequency-ratio limit by calculating finite-frequency exponents and scaling functions. This opens up a possibility to observe the evidence of the QPT in the Rabi model experimentally. Finally, going beyond the equilibrium setting, the influence of the quantum phase transition on the dynamics will be discussed. We show that Kibble-Zurek mechanism can precisely predict the universal scaling of the adiabatic dynamics of the Rabi model, which provides a first confirmation of the KZM prediction for a model without spatial degrees of freedom.

[1] Myung-Joong Hwang, Ricardo Puebla, and Martin B. Plenio, Phys. Rev. Lett. 115, 180404 (2015)

Hwang, Myung-Joong

2016-02-03T06:30:57Z

Jhgang:

[[Category:Speakers]]
* Postdoctoral Researcher at the [http://qubit-ulm.com University of Ulm, Germany].
* PhD from POSTECH in 2014.

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

Quantum phase transition and universal dynamics in the Rabi model

2016-02-03T06:30:27Z

Jhgang:

* Speaker: [[Chun, Seung-Hyun|Seung-Hyun Chun]] (Sejong University)
* Date: Monday February 16, 2016 17:00
* Place: Jeongho Seminar Room

In this talk, I will discuss our recent finding [1] that a two-level system coupled to a single-mode cavity field, described by the Rabi model, undergoes a second order quantum phase transition. Having only two constituent particles, the Rabi model is far from being in a thermodynamic limit; however, out study shows that an infinite ratio of the atomic transition frequency to the cavity frequency can play the role of thermodynamic limit. I first prove the quantum phase transition of the model by developing an effective low-energy theory for the infinite frequency-ratio limit. Then, in the sprit of finite-size scaling theory, I will discuss the influence of the criticality on a finite frequency-ratio limit by calculating finite-frequency exponents and scaling functions. This opens up a possibility to observe the evidence of the QPT in the Rabi model experimentally. Finally, going beyond the equilibrium setting, the influence of the quantum phase transition on the dynamics will be discussed. We show that Kibble-Zurek mechanism can precisely predict the universal scaling of the adiabatic dynamics of the Rabi model, which provides a first confirmation of the KZM prediction for a model without spatial degrees of freedom.

[1] Myung-Joong Hwang, Ricardo Puebla, and Martin B. Plenio, Phys. Rev. Lett. 115, 180404 (2015)

Quantum phase transition and universal dynamics in the Rabi model

2016-02-03T06:29:10Z

Jhgang: Created page with "In this talk, I will discuss our recent finding [1] that a two-level system coupled to a single-mode cavity field, described by the Rabi model, undergoes a second order quantu..."

In this talk, I will discuss our recent finding [1] that a two-level system coupled to a single-mode cavity field, described by the Rabi model, undergoes a second order quantum phase transition. Having only two constituent particles, the Rabi model is far from being in a thermodynamic limit; however, out study shows that an infinite ratio of the atomic transition frequency to the cavity frequency can play the role of thermodynamic limit. I first prove the quantum phase transition of the model by developing an effective low-energy theory for the infinite frequency-ratio limit. Then, in the sprit of finite-size scaling theory, I will discuss the influence of the criticality on a finite frequency-ratio limit by calculating finite-frequency exponents and scaling functions. This opens up a possibility to observe the evidence of the QPT in the Rabi model experimentally. Finally, going beyond the equilibrium setting, the influence of the quantum phase transition on the dynamics will be discussed. We show that Kibble-Zurek mechanism can precisely predict the universal scaling of the adiabatic dynamics of the Rabi model, which provides a first confirmation of the KZM prediction for a model without spatial degrees of freedom.

[1] Myung-Joong Hwang, Ricardo Puebla, and Martin B. Plenio, Phys. Rev. Lett. 115, 180404 (2015)

Growth and application of Dirac materials: graphene and topological insulator

2016-02-03T05:14:54Z

Jhgang:

* Speaker: [[Chun, Seung-Hyun|Seung-Hyun Chun]] (Sejong University)
* Date: Monday February 15, 2016 17:00
* Place: Jeongho Seminar Room

New materials possessing Dirac-cone surface states have been discovered in the 21st century, and the research of truly two-dimensional transport has begun. In addition to the interests on the fundamental physics, the potential of futuristic application is also intensively being explored.
Here, we summarize our activities in the growth and application of graphene and topological insulator thin films. With directly grown graphene by plasma enhanced chemical vapor deposition, we demonstrate high-performance light emitting diodes and bright visible light bulb.[1][2] Furthermore, simple graphene patterns have been obtained without the use of catalysts or lithography.[3]
High quality Bi2Se3 thin films were fabricated by molecular beam epitaxy. With the help of van der Waals epitaxy, ordered growth of topological insulator films were accomplished on amorphous substrates.[4] The transport properties at low temperature show the expected modulation by the gate voltage. Our approach for ordered growth of Bi2Se3 on amorphous dielectric surfaces presents considerable advantages for the fabrication of topological insulator heterojunctions with amorphous insulator or dielectric thin films.

References
[1] Yong Seung Kim et al., ACS Nano 8, 2230 (2014).
[2] Young Duck Kim et al., Nature Nanotechnology 10, 676 (2015).
[3] Yong Seung Kim et al., Nanoscale 6, 10100 (2014).
[4] Sahng-Kyoon Jerng et al., Nanoscale 5, 10618 (2013).

[[Category: Seminars]]
[[Category:Condensed Matter Seminars]]

Chun, Seung-Hyun

2016-02-03T05:14:07Z

Jhgang:

[[Category:Speakers]]
[[Category:Condensed Matter Speakers]]
* Professor of Physics
* Sejong University

==Contributions==
* [[Growth and application of Dirac materials: graphene and topological insulator]]

[[Category: Speakers]]
[[Category: Condensed Matter Speakers]]

Growth and application of Dirac materials: graphene and topological insulator

2016-02-03T05:12:34Z

Jhgang:

* Speaker: [[Chun, Seung-Hyun|Seung-Hyun Chun]] (Sejong University)
* Date: Wednesday February 15, 2016 17:00
* Place: Jeongho Seminar Room

New materials possessing Dirac-cone surface states have been discovered in the 21st century, and the research of truly two-dimensional transport has begun. In addition to the interests on the fundamental physics, the potential of futuristic application is also intensively being explored.
Here, we summarize our activities in the growth and application of graphene and topological insulator thin films. With directly grown graphene by plasma enhanced chemical vapor deposition, we demonstrate high-performance light emitting diodes and bright visible light bulb.[1][2] Furthermore, simple graphene patterns have been obtained without the use of catalysts or lithography.[3]
High quality Bi2Se3 thin films were fabricated by molecular beam epitaxy. With the help of van der Waals epitaxy, ordered growth of topological insulator films were accomplished on amorphous substrates.[4] The transport properties at low temperature show the expected modulation by the gate voltage. Our approach for ordered growth of Bi2Se3 on amorphous dielectric surfaces presents considerable advantages for the fabrication of topological insulator heterojunctions with amorphous insulator or dielectric thin films.

References
[1] Yong Seung Kim et al., ACS Nano 8, 2230 (2014).
[2] Young Duck Kim et al., Nature Nanotechnology 10, 676 (2015).
[3] Yong Seung Kim et al., Nanoscale 6, 10100 (2014).
[4] Sahng-Kyoon Jerng et al., Nanoscale 5, 10618 (2013).

[[Category: Seminars]]
[[Category:Condensed Matter Seminars]]

Chun, Seung-Hyun

2016-02-03T05:11:59Z

Jhgang:

[[Category:Speakers]]
[[Category:Condensed Matter Speakers]]
* Professor of Physics
* Sejong University

==Contributions==

[[Category: Speakers]]
[[Category: Condensed Matter Speakers]]

Growth and application of Dirac materials: graphene and topological insulator

2016-02-03T05:10:08Z

Jhgang:

* Speaker: [[Kim, Heon-Jung|Heon-Jung Kim]] (Sejong University)
* Date: Wednesday February 15, 2016 17:00
* Place: Jeongho Seminar Room

New materials possessing Dirac-cone surface states have been discovered in the 21st century, and the research of truly two-dimensional transport has begun. In addition to the interests on the fundamental physics, the potential of futuristic application is also intensively being explored.
Here, we summarize our activities in the growth and application of graphene and topological insulator thin films. With directly grown graphene by plasma enhanced chemical vapor deposition, we demonstrate high-performance light emitting diodes and bright visible light bulb.[1][2] Furthermore, simple graphene patterns have been obtained without the use of catalysts or lithography.[3]
High quality Bi2Se3 thin films were fabricated by molecular beam epitaxy. With the help of van der Waals epitaxy, ordered growth of topological insulator films were accomplished on amorphous substrates.[4] The transport properties at low temperature show the expected modulation by the gate voltage. Our approach for ordered growth of Bi2Se3 on amorphous dielectric surfaces presents considerable advantages for the fabrication of topological insulator heterojunctions with amorphous insulator or dielectric thin films.

References
[1] Yong Seung Kim et al., ACS Nano 8, 2230 (2014).
[2] Young Duck Kim et al., Nature Nanotechnology 10, 676 (2015).
[3] Yong Seung Kim et al., Nanoscale 6, 10100 (2014).
[4] Sahng-Kyoon Jerng et al., Nanoscale 5, 10618 (2013).

[[Category: Seminars]]
[[Category:Condensed Matter Seminars]]

Growth and application of Dirac materials: graphene and topological insulator

2016-02-03T05:09:53Z

Jhgang:

* Speaker: [[Kim, Heon-Jung|Heon-Jung Kim]] (Daegu University)
* Date: Wednesday February 15, 2016 17:00
* Place: Jeongho Seminar Room

New materials possessing Dirac-cone surface states have been discovered in the 21st century, and the research of truly two-dimensional transport has begun. In addition to the interests on the fundamental physics, the potential of futuristic application is also intensively being explored.
Here, we summarize our activities in the growth and application of graphene and topological insulator thin films. With directly grown graphene by plasma enhanced chemical vapor deposition, we demonstrate high-performance light emitting diodes and bright visible light bulb.[1][2] Furthermore, simple graphene patterns have been obtained without the use of catalysts or lithography.[3]
High quality Bi2Se3 thin films were fabricated by molecular beam epitaxy. With the help of van der Waals epitaxy, ordered growth of topological insulator films were accomplished on amorphous substrates.[4] The transport properties at low temperature show the expected modulation by the gate voltage. Our approach for ordered growth of Bi2Se3 on amorphous dielectric surfaces presents considerable advantages for the fabrication of topological insulator heterojunctions with amorphous insulator or dielectric thin films.

References
[1] Yong Seung Kim et al., ACS Nano 8, 2230 (2014).
[2] Young Duck Kim et al., Nature Nanotechnology 10, 676 (2015).
[3] Yong Seung Kim et al., Nanoscale 6, 10100 (2014).
[4] Sahng-Kyoon Jerng et al., Nanoscale 5, 10618 (2013).

[[Category: Seminars]]
[[Category:Condensed Matter Seminars]]

Growth and application of Dirac materials: graphene and topological insulator

2016-02-03T05:09:41Z

Jhgang:

* Speaker: [[Kim, Heon-Jung|Heon-Jung Kim]] (Daegu University)
* Date: Wednesday February 3, 2016 17:00
* Place: Jeongho Seminar Room

New materials possessing Dirac-cone surface states have been discovered in the 21st century, and the research of truly two-dimensional transport has begun. In addition to the interests on the fundamental physics, the potential of futuristic application is also intensively being explored.
Here, we summarize our activities in the growth and application of graphene and topological insulator thin films. With directly grown graphene by plasma enhanced chemical vapor deposition, we demonstrate high-performance light emitting diodes and bright visible light bulb.[1][2] Furthermore, simple graphene patterns have been obtained without the use of catalysts or lithography.[3]
High quality Bi2Se3 thin films were fabricated by molecular beam epitaxy. With the help of van der Waals epitaxy, ordered growth of topological insulator films were accomplished on amorphous substrates.[4] The transport properties at low temperature show the expected modulation by the gate voltage. Our approach for ordered growth of Bi2Se3 on amorphous dielectric surfaces presents considerable advantages for the fabrication of topological insulator heterojunctions with amorphous insulator or dielectric thin films.

References
[1] Yong Seung Kim et al., ACS Nano 8, 2230 (2014).
[2] Young Duck Kim et al., Nature Nanotechnology 10, 676 (2015).
[3] Yong Seung Kim et al., Nanoscale 6, 10100 (2014).
[4] Sahng-Kyoon Jerng et al., Nanoscale 5, 10618 (2013).

[[Category: Seminars]]
[[Category:Condensed Matter Seminars]]

Growth and application of Dirac materials: graphene and topological insulator

2016-02-03T05:09:33Z

Jhgang:

Growth and application of Dirac materials: graphene and topological insulator

2016-02-03T05:08:34Z

Jhgang: Created page with "New materials possessing Dirac-cone surface states have been discovered in the 21st century, and the research of truly two-dimensional transport has begun. In addition to the..."

New materials possessing Dirac-cone surface states have been discovered in the 21st century, and the research of truly two-dimensional transport has begun. In addition to the interests on the fundamental physics, the potential of futuristic application is also intensively being explored.
Here, we summarize our activities in the growth and application of graphene and topological insulator thin films. With directly grown graphene by plasma enhanced chemical vapor deposition, we demonstrate high-performance light emitting diodes and bright visible light bulb.[1][2] Furthermore, simple graphene patterns have been obtained without the use of catalysts or lithography.[3]
High quality Bi2Se3 thin films were fabricated by molecular beam epitaxy. With the help of van der Waals epitaxy, ordered growth of topological insulator films were accomplished on amorphous substrates.[4] The transport properties at low temperature show the expected modulation by the gate voltage. Our approach for ordered growth of Bi2Se3 on amorphous dielectric surfaces presents considerable advantages for the fabrication of topological insulator heterojunctions with amorphous insulator or dielectric thin films.

References
[1] Yong Seung Kim et al., ACS Nano 8, 2230 (2014).
[2] Young Duck Kim et al., Nature Nanotechnology 10, 676 (2015).
[3] Yong Seung Kim et al., Nanoscale 6, 10100 (2014).
[4] Sahng-Kyoon Jerng et al., Nanoscale 5, 10618 (2013).

Minsoo Kim

2016-01-21T07:29:18Z

Jhgang:

#redirect [[Kim, Minsoo]]

Valley-symmetry-preserved quasi-one-dimensional transport in ballistic graphene with gate-defined carrier guiding

2016-01-21T07:27:45Z

Jhgang:

* Speaker: [[Kim, Minsoo|Minsoo Kim]] (POSTECH)
* Date: Thursday March 31, 2016 17:00
* Place: Jeongho Seminar Room

Graphene nanoribbons, a one-dimensional (1D) graphene system, with zigzag edges are predicted to exhibit interesting electronic properties stemming from its Dirac band structure. However, to date, investigation of the properties is highly limited because of the defects and the roughness at the edges, which mix different valleys in graphene. Recent progress in preparing a high-quality graphene layer enables one to investigate the intrinsic carrier transport nature in the material. Here, we report the signature of conservation of valley symmetry in two types of quasi-1D ballistic transport devices; one is a quantum point contact (QPC) and another is an Aharonov-Bohm (AB) interferometer. Devices were fabricated on monolayer graphene with high carrier mobility, where the graphene was encapsulated between two thin hexagonal boron nitride (h-BN) layers. In measurements, charge carriers were confined in a potential well formed by the dual operation of the bottom and top gates and the four-terminal magnetoconductance (MC) was measured with varying the charge carrier density, dc bias, and temperature. Graphene in the device was in the ballistic regime, exhibiting the conductance quantization in steps of delta G = 4e^2/h starting from G = (2, 6), 10 e^2/h in a constricted conducting channel of QPC-type devices. This behavior is similar to the one observed in zigzag graphene nanoribbons having edge localized channels. Our tight-binding calculation shows that quasi-1D charge flow on a graphene plane acts a zigzag-type nanoribbon, unless it is perfectly aligned along the armchair direction. In the AB interferometry, we observed h/e periodic modulation of MC and the zero-field conductance minimum with a negative MC background. All these results strongly suggest that qausi-1D channels built in our devices preserve the intrinsic Dirac transport nature of carriers with its valley symmetry, which would be conveniently utilized for valleytronics in graphene.

[[Category: Seminars]]
[[Category: Young Scientists Seminars]]

Minsoo Kim

2016-01-21T07:27:00Z

Jhgang: Redirected page to Kim, Minsoo

#redirect [[Kim, Minsoo]]
[[Category:Speakers]]
[[Category:Young Scientists Speakers]]

김민수

2016-01-21T07:26:33Z

Jhgang: Redirected page to Kim, Minsoo

#redirect [[Kim, Minsoo]]
[[Category:Speakers]]
[[Category:Young Scientists Speakers]]

Kim, Minsoo

2016-01-21T07:23:20Z

Jhgang: Created page with "Category:Speakers Category:Young Scientists Speakers * PhD Student * Department of Physics, POSTECH * Email: [mailto:richgast@postech.ac.kr richgast(a)postech.ac.kr]..."

[[Category:Speakers]]
[[Category:Young Scientists Speakers]]
* PhD Student
* Department of Physics, POSTECH
* Email: [mailto:richgast@postech.ac.kr richgast(a)postech.ac.kr]

==Brief Biography==

Minsoo Kim received his Bachelor degree in Physics from POSTECH, department of physics in 2010. Subsequently He joined the group of Prof. Hu-Jong Lee's group at POSTECH as a Ph.D candidate so far.

He is interested in experimental studies on transport properties of layered semiconducting materials (graphene, topological insulator, dichalcogenide and their hetero-structures). Nowadays he is working on the research about quantum phenomena in ballistic graphene quasi-one-dimensional system with gate defined carrier guiding, to achieve electronic quantum optics based on graphene system. He also studies about two dimensional hybrid devices proximity coupled to superconductor, in particular focusing on its phase coherent properties [M. Kim et al., Sci. Rep. 7, 8715 (2015].

==Contributions==
# [[Valley-symmetry-preserved quasi-one-dimensional transport in ballistic graphene with gate-defined carrier guiding]]

김민수

2016-01-21T07:20:47Z

Jhgang: Redirected page to Minsoo Kim

#redirect [[Minsoo Kim]]
[[Category:Speakers]]
[[Category:Young Scientists Speakers]]

Minsoo Kim

2016-01-21T07:17:24Z

Jhgang: