我々の研究は、契約なしの下ディレクター、科学局、エネルギーSP2プログラムの米国務省のエネルギー基本科学のオフィスによってサポートされていました。 DE-AC02-05CH11231（STM計測の開発とデバイスの統合）。海軍研究（デバイス特性）、およびNSF賞のオフィスがありません。 CMMI-1235361（DI / DV撮影）。 STMデータを分析し、WSxMソフトウェアを使用してレンダリングされた。33 DWとAJBは国防科学技術大学院フェローシップ（NDSEG）プログラムを介して、国防総省（DoD）、32 CFR 168Aによってサポートされていました。

<ol>
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Authors have nothing to disclose.

STMの特徴付けのために、グラフェンデバイス製造の重要な目標は、1）欠陥の最小数と単層グラフェンを成長させる、2）大規模な、きれいな、均一な、かつ連続グラフェン表面を得る、3）との間に高抵抗のグラフェンデバイスの組み立てグラフェンとゲート（ すなわち、「ゲートリーク」）、4）個々のクーロン不純物を堆積します。 最初の目標は、グラフェン?...

グラフェンはその例外的、電気的、光学的、および機械的特性をもたらす独特の線形バンド構造を有する二次元材料である。1,9-16、その低エネルギーの電荷キャリアは、その相対、質量のないディラックフェルミオン15として記載されています動作は、従来のシステムでは、非相対論的電荷キャリアのそれとは大きく異なります。グラフェンへの不純物の様々な15-18制御された堆積は、摂動の範囲にこれらの相対論的電荷キャリアの応答の実験的研究のためのシンプルで汎用性の高いプラットフォームを提供します。このようなシステムの研究はグラフェン不純物は、化学ポテンシャル6,7をシフト実効誘電率8を変化させて、潜在的に電子的に媒介される超伝導9につながることができますことを明らかにしました。これらの研究6-8の多くはハイブリッドimpuritの特性を調整するための手段として、静電ゲーティングを採用しますY-グラフェンのデバイス。静電ゲートは、ヒステリシスのない、そのフェルミ準位に対して、材料の電子構造をシフトすることができます。2-5。また、このような不純物の電荷2または分子5の状態を調整することにより、静電ゲーティングは可逆的にハイブリッド不純物グラフェンのプロパティを変更することができますデバイス。 バックゲートグラフェンデバイスは、走査型トンネル顕微鏡（STM）の調査のための理想的なシステムを提供します。走査型トンネル顕微鏡は、導電性表面から数オングストローム離れて開催された鋭利な金属チップで構成されています。両者の先端面と、電子のトンネルとの間にバイアスを印加することにより。最も一般的なモードでは、定電流モードでは、1はラスタスキャン前後に先端をすることによって、試料表面のトポグラフィーをマッピングすることができます。また、試料の局所電子構造は、ローカルデに比例する微分コンダクタンスのdI / DVスペクトルを調べることによって研究することができます状態のnsity（LDOS）。この測定は、多くの場合、走査トンネル分光法（STS）と呼ばれます。別々のバイアス及びバックゲート電圧を制御することにより、不純物のグラフェンの応答は、これらのdI / DVスペクトルの挙動を分析することにより研究することができる。2-5 このレポートでは、クーロン不純物で飾らバックゲート型のグラフェン素子の製造は、概説されている（ 例えば、カルシウム原子を有料）。カルシウムおよびクラスタ吸着原子、グラフェン、六方晶窒化ホウ素（h-BN）、二酸化ケイ素（SiO 2）、及びバルクシリコン（ 図1）：デバイスは、（上から下へ）、次の順序での要素から構成されています。 H-BNは、グラフェンのための原子レベルで平坦と電気的に均質な基板を提供する絶縁性薄膜である。19-21 H-BNおよびSiO 2誘電体として作用し、バルクSiは、バックゲートとして機能します。 デバイスを製造するために、グラフェンは、まずelectroche上に成長させます化学蒸着（CVD）グラフェンの22-25清浄な触媒表面として働くmically研磨Cu箔22,23。 CVD成長は、メタン（CH 4）と水素（H 2）前駆体ガスは、Cu箔上にグ ​​ラフェン結晶のドメインを形成するために熱分解を受けます。これらのドメインは、成長し、最終的には多結晶グラフェンシートを形成し、一緒にマージしてください。25、得られたグラフェンをターゲット基板上に転写され、SiO 2上でのh-BNの機械的剥離19-21により調製したh-BN / SiO 2のチップ（/ Siの（100）チップ）、ポリビア （メチルメタクリレート）（PMMA）の転送。26-28 PMMA転送では、銅上のグラフェンは、第一のPMMAの層でスピンコートします。 PMMA /グラフェン/銅試料は、その後、銅をエッチング除去するエッチング液（ 例えば、FeCl 3を （AQ）28）、に浮かびます。未反応のPMMA /グラフェンサンプルは、h-BN / SiO 2のチップで釣られ、その後され、PMMA層を除去するために、有機溶媒（ 例えば、CH 2 Cl 2）とアルゴン/ H 2環境29,30で洗浄しました。得られたグラフェン/ H-BN /のSiO 2 / Siのサンプルは、その後、ワイヤボンディング、超高真空（UHV）サンプルプレート上の電気接点およびUHVチャンバ内でアニールされます。最後に、グラフェンデバイスは、クーロンの不純物（ 例えば、カルシウム原子を帯電した）と、その場で堆積し、STMによって研究されている。2-5

<table border="0" cellpadding="0" cellspacing="0">
	<tbody>
		<tr>
			<td>Cu foil</td>
			<td>Alfa Aesar</td>
			<td>CAS # 7440-50-8</td>
			<td>99.8% Cu</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td>Lot # F22X029</td>
			<td></td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td>Stock # 13382</td>
			<td></td>
		</tr>
		<tr>
			<td>Scotch Magic Tape</td>
			<td>Scotch&#174;</td>
			<td>N/A</td>
			<td>for exfoliation of hBN</td>
		</tr>
		<tr>
			<td>PMMA</td>
			<td>Micro Chem</td>
			<td>M23004 0500L 1GL</td>
			<td>A4</td>
		</tr>
		<tr>
			<td>FeCl3 resistant spoon</td>
			<td>Bel-Art ScienceWare</td>
			<td>367300015</td>
			<td>PTFE coated double ended&#160;</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>chemical spoon, 15 cm length</td>
		</tr>
		<tr>
			<td>FeCl3 (aq)</td>
			<td>Ricca Chemical</td>
			<td>3127-16</td>
			<td>40% w/v</td>
		</tr>
		<tr>
			<td>SiO2/Si(100) Chip</td>
			<td>NOVA Electric Materials</td>
			<td>HS39626-OX</td>
			<td>n/a</td>
		</tr>
		<tr>
			<td>h-BN</td>
			<td>K. Watanabe and</td>
			<td>Contact the group</td>
			<td>hexagonal Japanese BN (JBN)</td>
		</tr>
		<tr>
			<td></td>
			<td>T. Taniguchi Group</td>
			<td></td>
			<td></td>
		</tr>
		<tr>
			<td>Au(111)</td>
			<td>Agilent Technologies</td>
			<td>N9805B-FG</td>
			<td>Au(111) epitaxially grown on mica</td>
		</tr>
		<tr>
			<td>Sapphire</td>
			<td>Precision Ferrites &#38; Ceramic, Inc.</td>
			<td>Contact vendor</td>
			<td>P/N Sapphire Chips</td>
		</tr>
		<tr>
			<td></td>
			<td></td>
			<td></td>
			<td>0.22 X 0.125 X 0.015&#34;</td>
		</tr>
		<tr>
			<td>Ca source</td>
			<td>Trace Sciences International Corp.</td>
			<td>AS-3-Ca-5-S</td>
			<td>n/a</td>
		</tr>
		<tr>
			<td>Cu(100)</td>
			<td>Princeton Scientific</td>
			<td>Contact vendor</td>
			<td>Cu(100) single crystal</td>
		</tr>
		<tr>
			<td>Methane</td>
			<td>Praxair, Inc.</td>
			<td>ME 5.0RS-K</td>
			<td>Graphene growth precursor gas</td>
		</tr>
		<tr>
			<td>Hydrogen</td>
			<td>Praxair, Inc.</td>
			<td>HY 6.0RS-K</td>
			<td>Graphene growth precursor gas</td>
		</tr>
	</tbody>
</table>

fabrication of gate-tunable graphene devices for scanning tunneling microscopy studies with coulomb impurities

その相対低エネルギーの電荷キャリアにより、グラフェンおよび種々の不純物との間の相互作用は、新しい物理学及び電子デバイスを制御するための自​​由度を豊富につながります。具体的には、帯電したクーロン不純物から電位に応じて、グラフェンの電荷キャリアの挙動は、ほとんどの材料のものとは大きく異なることが予想されます。走査型トンネル顕微鏡（STM）、走査型トンネル分光法（STS）は、荷電した不純物の存在下で、グラフェンの電子構造の空間的及びエネルギー依存性の両方に関する詳細な情報を提供することができます。ハイブリッド不純物グラフェンデバイスの設計は、バックゲート型のグラフェン表面上に不純物の制御された堆積を用いて製造、制御可能にチューニンググラフェンの電子特性のために、いくつかの新規な方法を可能にした。1-8静電ゲーティングは、グラフェン中の電荷キャリア密度を制御することができますオセロすると能力BLY曲チャージ2および/ ​​または不純物の分子5の状態。本稿では、結合STM / STSの研究のための個々のクーロン不純物で飾らゲート可変グラフェン素子の製造プロセスの概要を説明します。2-5これらの研究は、ハイブリッドグラフェンデバイスを設計するための貴重な基礎となる物理学への洞察だけでなく、道標を提供しています。

図1は、バックゲート型のグラフェン素子の概略図を示しています。ワイヤボンディングながらワイヤボンディングのSiバルクバックゲートを外部回路に装置を接続する電極に、電気的にUHVサンプルプレート敷地グラフェンへのAu / Tiの接触を。バックゲーティングデバイスが、（STMチップによって制御される）所与のサンプルバイアスにおけるクーロン不純物の充電状態は、異な...

Watch this Scientific Journal Video about Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities at JoVE.com

Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities

This paper details the fabrication process of a gate-tunable graphene device, decorated with Coulomb impurities for scanning tunneling microscopy studies. Mapping the spatially dependent electronic structure of graphene in the presence of charged impurities unveils the unique behavior of its relativistic charge carriers in response to a local Coulomb potential.

クーロン不純物を走査トンネル顕微鏡研究のためのゲート - 調整可能なグラフェンデバイスの作製

Owing to its relativistic low-energy charge carriers, the interaction between graphene and various impurities leads to a wealth of new physics and degrees ...

fabrication-gate-tunable-graphene-devices-for-scanning-tunneling

Research

JoVE Journal

Engineering

15.3K ビュー.  University of California at Berkeley. This paper details the fabrication process of a gate-tunable graphene device, decorated with Coulomb impurities for scanning tunneling microscopy studies. Mapping the spatially dependent electronic structure of graphene in the presence of charged impurities unveils the unique behavior of its relativistic charge carriers in response to a local Coulomb potential.

ビデオ: Fabrication of Gate-tunable Graphene Devices for Scanning Tunneling Microscopy Studies with Coulomb Impurities

Fabrication of Fully Solution Processed Inorganic Nanocrystal Photovoltaic Devices

We demonstrate a method for the preparation of fully solution processed inorganic solar cells from a spin and spray coating deposition of nanocrystal inks. For the photoactive absorber layer, colloidal CdTe and CdSe nanocrystals (3-5 nm) are synthesized using an inert hot injection technique and cleaned with precipitations to remove excess starting reagents. Similarly, gold nanocrystals (3-5 nm) are synthesized under ambient conditions and dissolved in organic solvents. In addition, precursor solutions for transparent conductive indium tin oxide (ITO) films are prepared from solutions of indium and tin salts paired with a reactive oxidizer. Layer-by-layer, these solutions are deposited onto a glass substrate following annealing (200-400 &#176;C) to build the nanocrystal solar cell (glass/ITO/CdSe/CdTe/Au). Pre-annealing ligand exchange is required for CdSe and CdTe nanocrystals where films are dipped in NH4Cl:methanol to replace long-chain native ligands with small inorganic Cl- anions. NH4Cl(s) was found to act as a catalyst for the sintering reaction (as a non-toxic alternative to the conventional CdCl2(s) treatment) leading to grain growth (136&#177;39 nm) during heating. The thickness and roughness of the prepared films are characterized with SEM and optical profilometry. FTIR is used to determine the degree of ligand exchange prior to sintering, and XRD is used to verify the crystallinity and phase of each material. UV/Vis spectra show high visible light transmission through the ITO layer and a red shift in the absorbance of the cadmium chalcogenide nanocrystals after thermal annealing. Current-voltage curves of completed devices are measured under simulated one sun illumination. Small differences in deposition techniques and reagents employed during ligand exchange have been shown to have a profound influence on the device properties. Here, we examine the effects of chemical (sintering and ligand exchange agents) and physical treatments (solution concentration, spray-pressure, annealing time and annealing temperature) on photovoltaic device performance.

This protocol describes the synthesis and solution deposition of inorganic nanocrystals layer by layer to produce thin film electronics on non-conductive surfaces. Solvent-stabilized inks can produce complete photovoltaic devices on glass substrates via spin and spray coating following post-deposition ligand exchange and sintering.

完全に解決策が処理無機ナノ結晶太陽電池素子の作製

We demonstrate a method for the preparation of fully solution processed inorganic solar cells from a spin and spray coating deposition of nanocrystal ...

工学

Solvent Bonding for Fabrication of PMMA and COP Microfluidic Devices

Thermoplastic microfluidic devices offer many advantages over those made from silicone elastomers, but bonding procedures must be developed for each thermoplastic of interest. Solvent bonding is a simple and versatile method that can be used to fabricate devices from a variety of plastics. An appropriate solvent is added between two device layers to be bonded, and heat and pressure are applied to the device to facilitate the bonding. By using an appropriate combination of solvent, plastic, heat, and pressure, the device can be sealed with a high quality bond, characterized as having high bond coverage, bond strength, optical clarity, durability over time, and low deformation or damage to microfeature geometry. We describe the procedure for bonding devices made from two popular thermoplastics, poly(methyl-methacrylate) (PMMA), and cyclo-olefin polymer (COP), as well as a variety of methods to characterize the quality of the resulting bonds, and strategies to troubleshoot low quality bonds. These methods can be used to develop new solvent bonding protocols for other plastic-solvent systems.

Solvent bonding is a simple and versatile method for fabricating thermoplastic microfluidic devices with high quality bonds. We describe a protocol to achieve strong, optically clear bonds in PMMA and COP microfluidic devices that preserve microfeature details, by a judicious combination of pressure, temperature, an appropriate solvent, and device geometry.

PMMAおよびCOPマイクロ流体デバイスの作製のための溶剤接着

Thermoplastic microfluidic devices offer many advantages over those made from silicone elastomers, but bonding procedures must be developed for each ...

Scanning Light Scattering Profiler (SLPS) Based Methodology to Quantitatively Evaluate Forward and Backward Light Scattering from Intraocular Lenses

The scanning light scattering profiler (SLSP) methodology has been developed for the full-angle quantitative evaluation of forward and backward light scattering from intraocular lenses (IOLs) using goniophotometer principles. This protocol describes the SLSP platform and how it employs a 360&#176; rotational photodetector sensor that is scanned around an IOL sample while recording the intensity and location of scattered light as it passes through the IOL medium. The SLSP platform can be used to predict, non-clinically, the propensity for current and novel IOL designs and materials to induce light scatter. Non-clinical evaluation of light scattering properties of IOLs can significantly reduce the number of patient complaints related to unwanted glare, glistening, optical defects, poor image quality, and other phenomena associated with the unintended light scattering. Future studies should be conducted to correlate SLSP data with clinical results to help identify which measured light scatter is most problematic for patients that have undergone cataract surgery subsequent to IOL implantation.

Scanning Light Scattering Profiler SLPS Based Methodology to Quantitatively Evaluate Forward and Backward Light Scattering from Intraocular Lenses

This protocol describes the scanning light scattering profiler (SLSP) that enables the full-angle quantitative evaluation of forward and backward scattering of light from intraocular lenses (IOLs) using goniophotometer principles.

眼内レンズからの前方散乱光および後方散乱光を定量的に評価するための走査型光散乱プロファイラ（SLPS）に基づく方法論

The scanning light scattering profiler (SLSP) methodology has been developed for the full-angle quantitative evaluation of forward and backward light ...

All-electronic Nanosecond-resolved Scanning Tunneling Microscopy: Facilitating the Investigation of Single Dopant Charge Dynamics

The miniaturization of semiconductor devices to scales where small numbers of dopants can control device properties requires the development of new techniques capable of characterizing their dynamics. Investigating single dopants requires sub-nanometer spatial resolution, which motivates the use of scanning tunneling microscopy (STM). However, conventional STM is limited to millisecond temporal resolution. Several methods have been developed to overcome this shortcoming, including all-electronic time-resolved STM, which is used in this study to examine dopant dynamics in silicon with nanosecond resolution. The methods presented here are widely accessible and allow for local measurement of a wide variety of dynamics at the atomic scale. A novel time-resolved scanning tunneling spectroscopy technique is presented and used to efficiently search for dynamics.

We demonstrate an all-electronic method to observe nanosecond-resolved charge dynamics of dopant atoms in silicon with a scanning tunneling microscope.

すべて電子ナノ秒分解走査型トンネル顕微鏡: 単一ドーパントの電荷ダイナミクスの調査を促進します。

The miniaturization of semiconductor devices to scales where small numbers of dopants can control device properties requires the development of new ...

Atmospheric Pressure Fabrication of Large-Sized Single-Layer Rectangular SnSe Flakes

Tin selenide (SnSe) belongs to the family of layered metal chalcogenide materials with a buckled structure like phosphorene, and has shown potential for applications in two-dimensional nanoelectronics devices. Although many methods to synthesize SnSe nanocrystals have been developed, a simple way to fabricate large-sized single-layer SnSe flakes remains a great challenge. Herein, we show the experimental method to directly grow large-sized single-layer rectangular SnSe flakes on commonly used SiO2/Si insulating substrates using a straightforward two-step fabrication method in an atmospheric pressure quartz tube furnace system. The single-layer rectangular SnSe flakes with an average thickness of ~6.8 &#197; and lateral dimensions of about 30 &#181;m &#215; 50 &#181;m were fabricated by a combination of vapor transport deposition technique and nitrogen etching route. We characterized the morphology, microstructure, and electrical properties of the rectangular SnSe flakes and obtained excellent crystallinity and good electronic properties. This article about the two-step fabrication method can help researchers grow other similar two-dimensional, large-sized, single-layer materials using an atmospheric pressure system.

A protocol is presented demonstrating a two-step fabrication technique to grow large-sized single-layer rectangular shaped SnSe flakes on low-cost SiO2/Si dielectrics wafers in an atmospheric pressure quartz tube furnace system.

大型単層長方形 SnSe フレークの大気圧作製

Tin selenide (SnSe) belongs to the family of layered metal chalcogenide materials with a buckled structure like phosphorene, and has shown potential for ...

Fabrication of Magnetic Nanostructures on Silicon Nitride Membranes for Magnetic Vortex Studies Using Transmission Microscopy Techniques

Electron and x-ray magnetic microscopies allow for high-resolution magnetic imaging down to tens of nanometers. However, the samples need to be prepared on transparent membranes which are very fragile and difficult to manipulate. We present processes for the fabrication of samples with magnetic micro- and nanostructures with spin configurations forming magnetic vortices suitable for Lorentz transmission electron microscopy and magnetic transmission x-ray microscopy studies. The samples are prepared on silicon nitride membranes and the fabrication consists of a spin coating, UV and electron-beam lithography, the chemical development of the resist, and the evaporation of the magnetic material followed by a lift-off process forming the final magnetic structures. The samples for the Lorentz transmission electron microscopy consist of magnetic nanodiscs prepared in a single lithography step. The samples for the magnetic x-ray transmission microscopy are used for time-resolved magnetization dynamic experiments, and magnetic nanodiscs are placed on a waveguide which is used for the generation of repeatable magnetic field pulses by passing an electric current through the waveguide. The waveguide is created in an extra lithography step.

A protocol for the fabrication of magnetic micro- and nanostructures with spin configurations forming magnetic vortices suitable for transmission electron microscopy (TEM) and magnetic transmission x-ray microscopy (MTXM) studies is presented.

磁気渦の研究伝達顕微鏡検査の技術を使用してシリコン窒化膜の磁性ナノ構造の作製

Electron and x-ray magnetic microscopies allow for high-resolution magnetic imaging down to tens of nanometers. However, the samples need to be prepared ...

Fabrication of Refractive-index-matched Devices for Biomedical Microfluidics

The use of microfluidic devices has emerged as a defining tool for biomedical applications. When combined with modern microscopy techniques, these devices can be implemented as part of a robust platform capable of making simultaneous complementary measurements. The primary challenge created by the combination of these two techniques is the mismatch in refractive index between the materials traditionally used to make microfluidic devices and the aqueous solutions typically used in biomedicine. This mismatch can create optical artifacts near the channel or device edges. One solution is to reduce the refractive index of the material used to fabricate the device by using a fluorinated polymer such as MY133-V2000 whose refractive index is similar to that of water (n = 1.33). Here, the construction of a microfluidic device made out of MY133-V2000 using soft lithography techniques is demonstrated, using O2 plasma in conjunction with an acrylic holder to increase the adhesion between the MY133-V2000 fabricated device and the polydimethylsiloxane (PDMS) substrate. The device is then tested by incubating it filled with cell culture media for 24 h to demonstrate the ability of the device to maintain cell culture conditions during the course of a typical imaging experiment. Finally, quantitative phase microscopy (QPM) is used to measure the distribution of mass within the live adherent cells in the microchannel. This way, the increased precision, enabled by fabricating the device from a low index of refraction polymer such as MY133-V2000 in lieu of traditional soft lithography materials such as PDMS, is demonstrated. Overall, this approach for fabricating microfluidic devices can be readily integrated into existing soft lithography workflows in order to reduce optical artifacts and increase measurement precision.

This protocol describes the fabrication of microfluidic devices from MY133-V2000 to eliminate artifacts that often arise in microchannels due to the mismatching refractive indices between microchannel structures and an aqueous solution. This protocol uses an acrylic holder to compress the encapsulated device, improving adhesion both chemically and mechanically.

生体の屈折率-屈折率整合素子の作製

The use of microfluidic devices has emerged as a defining tool for biomedical applications. When combined with modern microscopy techniques, these devices ...

Fabrication of Three-Dimensional Graphene-Based Polyhedrons via Origami-Like Self-Folding

The assembly of two-dimensional (2D) graphene into three-dimensional (3D) polyhedral structures while preserving the graphene's excellent inherent properties has been of great interest for the development of novel device applications. Here, fabrication of 3D, microscale, hollow polyhedrons (cubes) consisting of a few layers of 2D graphene or graphene oxide sheets via an origami-like self-folding process is described. This method involves the use of polymer frames and hinges, and aluminum oxide/chromium protection layers that reduce tensile, spatial, and surface tension stresses on the graphene-based membranes when the 2D nets are transformed into 3D cubes. The process offers control of the size and shape of the structures as well as parallel production. In addition, this approach allows the creation of surface modifications by metal patterning on each face of the 3D cubes. Raman spectroscopy studies show the method allows the preservation of the intrinsic properties of the graphene-based membranes, demonstrating the robustness of our method.

Fabrication of Three-Dimensional Graphene-Based Polyhedrons via Origami-Like Self-Folding

Here, we present a protocol for fabrication of 3D graphene-based polyhedrons via origami-like self-folding.

三次元グラフェンを用いた多面体を介して折り紙のような自己折りたたみの作製

The assembly of two-dimensional (2D) graphene into three-dimensional (3D) polyhedral structures while preserving the graphene's excellent inherent ...

Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope

The quest to understand correlated electronic systems has pushed the frontiers of experimental measurements toward the development of new experimental techniques and methodologies. Here we use a novel home-built uniaxial-strain device integrated into our variable temperature scanning tunneling microscope that enables us to controllably manipulate in-plane uniaxial strain in samples and probe their electronic response at the atomic scale. Using scanning tunneling microscopy (STM) with spin-polarization techniques, we visualize antiferromagnetic (AFM) domains and their atomic structure in Fe1+yTe samples, the parent compound of iron-based superconductors, and demonstrate how these domains respond to applied uniaxial strain. We observe the bidirectional AFM domains in the unstrained sample, with an average domain size of ~50-150 nm, to transition into a single unidirectional domain under applied uniaxial strain. The findings presented here open a new direction to utilize a valuable tuning parameter in STM, as well as other spectroscopic techniques, both for tuning the electronic properties as for inducing symmetry breaking in quantum material systems.

Visualizing Uniaxial-strain Manipulation of Antiferromagnetic Domains in Fe1+YTe Using a Spin-polarized Scanning Tunneling Microscope

Using uniaxial strain combined with spin-polarized scanning tunneling microscopy, we visualize and manipulate the antiferromagnetic domain structure of Fe1+yTe, the parent compound of iron-based superconductors.

一軸歪 Fe1 +Yスピン偏極走査トンネル顕微鏡を使用して Te の反強磁性ドメイン操作を可視化

The quest to understand correlated electronic systems has pushed the frontiers of experimental measurements toward the development of new experimental ...

Fabrication of Nanoheight Channels Incorporating Surface Acoustic Wave Actuation via Lithium Niobate for Acoustic Nanofluidics

Controlled nanoscale manipulation of fluids is known to be exceptionally difficult due to the dominance of surface and viscous forces. Megahertz-order surface acoustic wave (SAW) devices generate tremendous acceleration on their surface, up to 108 m/s2, in turn responsible for many of the observed effects that have come to define acoustofluidics: acoustic streaming and acoustic radiation forces. These effects have been used for particle, cell, and fluid manipulation at the microscale, although more recently SAW has been used to produce similar phenomena at the nanoscale through an entirely different set of mechanisms. Controllable nanoscale fluid manipulation offers a broad range of opportunities in ultrafast fluid pumping and biomacromolecule dynamics useful for physical and biological applications. Here, we demonstrate nanoscale-height channel fabrication via room-temperature lithium niobate (LN) bonding integrated with a SAW device. We describe the entire experimental process including nano-height channel fabrication via dry etching, plasma-activated bonding on lithium niobate, the appropriate optical setup for subsequent imaging, and SAW actuation. We show representative results for fluid capillary filling and fluid draining in a nanoscale channel induced by SAW. This procedure offers a practical protocol for nanoscale channel fabrication and integration with SAW devices useful to build upon for future nanofluidics applications.

We demonstrate fabrication of nanoheight channels with the integration of surface acoustic wave actuation devices upon lithium niobate for acoustic nanofluidics via liftoff photolithography, nano-depth reactive ion etching, and room-temperature plasma surface-activated multilayer bonding of single-crystal lithium niobate, a process similarly useful for bonding lithium niobate to oxides.

音響ナノ流体工学のための表面音響波作動を組み込んだナノ高さチャネルの作製

Controlled nanoscale manipulation of fluids is known to be exceptionally difficult due to the dominance of surface and viscous forces. Megahertz-order ...