Isu tinoshandisa nguva- uye angle-yakagadziriswa photoemission spectroscopy (tr-ARPES) kuongorora ultrafast charge transfer in epitaxial heterostructure yakagadzirwa monolayer WS2 uye graphene. Iyi heterostructure inosanganisa mabhenefiti e-direct-gap semiconductor ine yakasimba spin-orbit coupling uye yakasimba mwenje-matter kudyidzana neaya esemimetal hosting massless vatakuri vane yakanyanya kukwirira kufamba uye refu spin yehupenyu. Tinoona kuti, pashure photoexcitation panguva resonance kuti A-exciton muna WS2, maburi photoexcited nokukurumidza kutamira graphene layer apo photoexcited maerekitironi anoramba ari WS2 layer. Mhedzisiro yechaji-yakaparadzaniswa yenguva pfupi inowanikwa iine hupenyu hwe ~ 1 ps. Isu tinopa zvatakawana kune misiyano yekuparadzira chikamu nzvimbo inokonzerwa nekuenderana kweWS2 nemagraphene mabhendi sezvakaratidzwa nepamusoro-resolution ARPES. Mukubatana ne spin-selective optical excitation, iyo yakaferefetwa WS2/graphene heterostructure inogona kupa puratifomu yeinoshanda jekiseni repini mu graphene.
Kuwanikwa kwezvinhu zvakawanda zvakasiyana-siyana-mativi maviri kwakavhura mukana wekugadzira riwaya pakupedzisira rakatetepa heterostructures ine mashandiro matsva anoenderana neakarongedzerwa dielectric screening uye akasiyana-siyana anokonzeresa mhedzisiro (1-3). Zvishandiso zvehumbowo zvezvishandiso zvenguva yemberi mumunda wemagetsi uye optoelectronics zvakaonekwa (4-6).
Pano, isu tinotarisisa epitaxial van der Waals heterostructures inosanganisira monolayer WS2, yakananga-gap semiconductor ine yakasimba spin-orbit coupling uye yakakura kupatsanurwa kwebhendi chimiro nekuda kwekutyoka inversion symmetry (7), uye monolayer graphene, semimetal. ine conical bhendi chimiro uye yakanyanya kukwirira inotakura kufamba (8), inokura pahydrogen-yakamiswa SiC(0001). Chekutanga zviratidzo zve ultrafast charge transfer (9-15) uye pedyo-induced spin-orbit coupling effects (16-18) inoita WS2/graphene uye yakafanana heterostructures inovimbisa vamiriri venguva yemberi optoelectronic (19) uye optospintronic (20) maapplication.
Isu takagadzirira kuburitsa nzira dzekuzorora dzemafotogenerated electron-hole pairs muWS2/graphene ine nguva- uye angle-yakagadziriswa photoemission spectroscopy (tr-ARPES). Nechinangwa ichocho, isu tinofadza iyo heterostructure ine 2-eV pombi pulses resonant kune A-exciton muWS2 (21, 12) uye eject photoelectrons ine kechipiri-inononoka probe pulse pa 26-eV photon simba. Isu tinosarudza kinetic simba uye emission angle yemafotoelectrons ane hemispherical analyzer sebasa rekunonoka kwepombi-probe kuwana mukana wekukurumidza-, simba-, uye nguva-yakagadziriswa inotakura masimba. Iyo simba uye nguva yekugadzirisa ndeye 240 meV uye 200 fs, zvichiteerana.
Mhedzisiro yedu inopa humbowo hwakananga hweiyo ultrafast charge transfer pakati peepitaxially aligned layers, zvichisimbisa zviratidzo zvekutanga zvichibva pane ese-optical tekinoroji mumawoko akaungana heterostructures ane arbitrary azimuthal alignment yezvikamu (9-15). Pamusoro pezvo, isu tinoratidza kuti iyi yekuchaja yekufambisa yakanyanya asymmetric. Zviyero zvedu zvinoburitsa yaimbove isina kucherechedzwa yekuchaja-yakapatsanurwa yenguva pfupi ine maerekitironi anofadza uye maburi ari muWS2 uye graphene layer, zvichiteerana, inorarama ~1 ps. Isu tinoturikira zvatinowana maererano nemisiyano yekuparadzira chikamu nzvimbo yeelectron uye gomba kuchinjisa kunokonzerwa nekuenderana kweWS2 nemagraphene mabhendi sekuratidzwa kwakakwira-resolution ARPES. Yakasanganiswa ne spin- uye valley-selective optical excitation (22–25) WS2/graphene heterostructures inogona kupa chikuva chitsva cheunoshanda ultrafast optical spin jekiseni mugraphene.
Mufananidzo 1A unoratidza chiyero chepamusoro che ARPES chakawanikwa nehelium rambi yebhandi chimiro pamwe ne ΓK-direction ye epitaxial WS2 / graphene heterostructure. Iyo Dirac cone inowanikwa iine gomba-doped neiyo Dirac point iri ~ 0.3 eV pamusoro pekuenzana kwemakemikari anogona. Pamusoro peiyo spin-split WS2 valence band inowanikwa iri ~ 1.2 eV pazasi peyakaenzana kemikari inogoneka.
(A) Equilibrium photocurrent yakayerwa pamwe ne ΓK-direction ine unpolarized helium rambi. (B) Photocurrent for negative pump-probe kunonoka kuyerwa nep-polarized extreme ultraviolet pulses pa 26-eV photon simba. Dashed grey uye mitsara mitsvuku inoratidza nzvimbo yemaprofiles emutsara anoshandiswa kubvisa nzvimbo dzepamusoro dzenguva pfupi mumufananidzo 2. (C) Pump-induced shanduko ye photocurrent 200 fs mushure me photoexcitation papombi photon simba re 2 eV ine pombi fluence. ye2 mJ/cm2. Kuwana uye kurasikirwa kwemafotoelectrons kunoratidzwa mutsvuku uye bhuruu, zvichiteerana. Mabhokisi anoratidza nzvimbo yekubatanidza yepombi-probe traces inoratidzwa muFig. 3.
Mufananidzo 1B unoratidza tr-ARPES snapshot yebhandi chimiro chiri pedyo neWS2 uye graphene K-points yakayerwa ne100-fs yakanyanyisa ultraviolet pulses pa 26-eV photon simba pakunonoka kwepombi-probe isati yasvika pombi yepombi. Pano, kupatsanurwa kwepini hakuna kugadziriswa nekuda kwekuderedzwa kwemuenzaniso uye kuvapo kwe2-eV pombi pulse iyo inokonzeresa kushaja kwenzvimbo kuwedzera kweiyo spectral maficha. Mufananidzo 1C unoratidza shanduko yepombi-induced ye photocurrent maererano neFig. 1B pane pombi-probe inononoka ye 200 fs apo chiratidzo chepombi-probe chinosvika pakukwirira kwayo. Mavara matsvuku uye ebhuruu anoratidza kuwana uye kurasikirwa kwemafotoelectrons, zvichiteerana.
Kuti tiongorore kusimba kwesimba iri mune zvakadzama, tinotanga taziva nzvimbo dzepamusoro-soro dzeWS2 valence bhendi uye graphene π-bhendi pamwe nemitsara yakadhindwa muFig. 1B sekutsanangurwa kwazvino muSupplementary Materials. Tinoona kuti WS2 valence bhendi inoshanduka ichikwira ne90 meV (Fig. 2A) uye graphene π-bhendi inoshanduka ichidzika ne50 meV (Fig. 2B). Iyo exponential lifetime yeaya mashifiti anowanikwa ari 1.2 ± 0.1 ps yevalence bhendi reWS2 uye 1.7 ± 0.3 ps yegraphene π-bhendi. Aya mashefu epamusoro anopa humbowo hwekutanga hwekuchaja kwechinguvana kwezvikamu zviviri, uko kuwedzera kwakanaka (negative) kuchaja kunowedzera (kunoderera) simba rinosunga renyika dzemagetsi. Ziva kuti upshift yeWS2 valence bhendi ndiyo ine basa rechiratidzo chepombi-probe yakakurumbira munzvimbo yakanyorwa nebhokisi dema muFig. 1C.
Shanduko panzvimbo yepamusoro yeWS2 valence bhendi (A) uye graphene π-bhendi (B) sebasa rekunonoka kwepombi-probe pamwe chete neexponential fit (mitsetse makobvu). Hupenyu hwekuchinja kweWS2 mu (A) ndeye 1.2 ± 0.1 ps. Hupenyu hwekuchinja kwegraphene mu (B) ndeye 1.7 ± 0.3 ps.
Zvadaro, tinobatanidza chiratidzo chepombi-probe pamusoro penzvimbo dzakaratidzwa nemabhokisi ane mavara muFig. 1C uye tinoronga zvikamu zvinoguma sebasa rekunonoka kwepombi-probe mumufananidzo 3. Curve 1 mumufananidzo 3 inoratidza maitiro ekugadzirisa photoexcited vatakuri pedyo nechepasi pe conduction bhendi yeWS2 layer ine hupenyu hwe1.1 ± 0.1 ps inowanikwa kubva kune exponential fit kusvika iyo data (ona iyo Supplementary Materials).
Pump-probe traces sebasa rekunonoka kunowanikwa nekubatanidza photocurrent pamusoro penzvimbo inoratidzwa nemabhokisi muFig. 1C. Mitsetse yakakora ndeye exponential inoenderana nedata. Curve (1) Chinguva chinotakura vanhu muboka rekuita reWS2. Curve (2) Pombi-probe chiratidzo che π-bhendi regraphene pamusoro pekuenzana kwekemikari. Curve (3) Pombi-probe chiratidzo che π-bhendi regraphene pazasi peequilibrium kemikari inogoneka. Curve (4) Net pombi-probe chiratidzo muvalence bhendi reWS2. Hupenyu hwese hunowanikwa huri 1.2 ± 0.1 ps mu (1), 180 ± 20 fs (kuwana) uye ~ 2 ps (kurasikirwa) mu (2), uye 1.8 ± 0.2 ps mu (3).
Mune curves 2 uye 3 yeFig. 3, tinoratidza pombi-probe chiratidzo chegraphene π-band. Tinoona kuti kuwana maerekitironi pamusoro peequilibrium kemikemikari inogona (curve 2 muFig. 3) ine hupenyu hupfupi zvikuru (180 ± 20 fs) zvichienzaniswa nekurasikirwa kwemaerekitironi pasi pekuenzanisa kwekemikari inogona (1.8 ± 0.2 ps mu curve 3). Mufananidzo 3). Uyezve, kuwana kwekutanga kwe photocurrent mu curve 2 yeFig. 3 inowanikwa kushandura kurasikirwa pa t = 400 fs nehupenyu hwe ~ 2 ps. The asymmetry pakati pekuwana uye kurasikirwa kunowanikwa kusipo mupombi-probe chiratidzo chekuvhara monolayer graphene (ona fig. S5 muSupplementary Materials), zvichiratidza kuti asymmetry inokonzerwa nekubatanidza interlayer muWS2 / graphene heterostructure. Kucherechedza kwekuwana kwenguva pfupi uye kurasikirwa kwekugara kwenguva refu kumusoro uye pasi pehutano hwemakemikari ekuenzanisa, zvichienderana, zvinoratidza kuti maerekitironi anobviswa zvakanaka kubva pa graphene layer pa photoexcitation ye heterostructure. Somugumisiro, girafu ye graphene inova inopomerwa zvakanaka, iyo inopindirana nekuwedzera kwekusunga simba re π-bhendi rinowanikwa mumufananidzo 2B. Iko kuderera kwe-π-bhendi kunobvisa muswe wepamusoro-simba wekuenzana kugoverwa kweFermi-Dirac kubva pamusoro pehutano hwemakemikari ekuenzanisa, iyo inotsanangura chikamu chekuchinja kwechiratidzo chepombi-probe chiratidzo mu curve 2 yeFig. 3. Tichaita ratidza pazasi kuti chiitiko ichi chinowedzerwazve nekurasikirwa kwenguva pfupi kwemaerekitironi mu π-bhendi.
Mamiriro ezvinhu aya anotsigirwa net net pump-probe signal yeWS2 valence band mucurve 4 yeFig. 3. Iyi data yakawanikwa nekubatanidza kuverenga pamusoro penzvimbo yakapiwa nebhokisi dema muFig. 1B inobata ma electrons anotorwa kubva bhendi revalence pakunonoka kwepombi-probe. Mukati meyedzo yekukanganisa mabhawa, hatiwane chiratidzo chekuvapo kwemakomba mubhendi revalence reWS2 chero kunonoka kwepombi-probe. Izvi zvinoratidza kuti, mushure mekuita photoexcitation, maburi aya anokurumidza kuzadzwa pachiyero chenguva pfupi kana tichienzanisa nekugadzirisa kwedu kwenguva.
Kuti tipe humbowo hwekupedzisira hwekufungidzira kwedu kwekuparadzana kwekuchaja kwekupedzisira muWS2/graphene heterostructure, tinoona huwandu hwemaburi anoendeswa kune graphene layer sekutsanangurwa kwazvino muSupplementary Materials. Muchidimbu, iyo yenguva pfupi yemagetsi kugovera kweiyo π-bhendi yakaiswa neFermi-Dirac kugovera. Huwandu hwemakomba hwakabva hwaverengerwa kubva kune zvakakonzera kukosha kwechinguvana kemikari inogona uye tembiricha yemagetsi. Chigumisiro chinoratidzwa mumufananidzo 4. Tinoona kuti nhamba yose ~ 5 × 1012 maburi / cm2 inotamiswa kubva kuWS2 kusvika kugraphene nehupenyu hwehupenyu hwe1.5 ± 0.2 ps.
Shanduko yehuwandu hwemakomba ari mu π-bhendi sebasa rekunonoka kwepombi-probe pamwe neexponential fit inoburitsa hupenyu hwese 1.5 ± 0.2 ps.
Kubva pane zvakawanikwa muFig. 2 kusvika ku4, iyo inotevera microscopic mufananidzo weiyo ultrafast charge transfer muWS2/graphene heterostructure inobuda (Fig. 5). Photoexcitation yeWS2/graphene heterostructure pa2 eV inonyanya kuzara neA-exciton muWS2 (Fig. 5A). Kuwedzera kuwedzeredza kwemagetsi mhiri kweDirac point mugraphene pamwe nepakati peWS2 nemagraphene mabhendi zvinogoneka zvine simba asi zvisingaite zvakanyanya. Maburi ephotoexcited ari mubhendi revalence reWS2 anozadzwazve nemaerekitironi anobva kugraphene π-bhendi pachikamu chenguva pfupi kana tichienzanisa nekugadzirisa kwedu kwenguva (Fig. 5A). Maerekitironi ephotoexcited ari mubhendi rekufambisa reWS2 ane hupenyu hwe ~ 1 ps (Fig. 5B). Zvisinei, zvinotora ~ 2 ps kuzadza zvakare maburi mugraphene π-band (Fig. 5B). Izvi zvinoratidza kuti, kunze kwekutamisa maerekitironi zvakananga pakati peWS2 conduction bhendi uye graphene π-bhendi, dzimwe nzira dzekuzorora-pamwe kuburikidza neyakaremara nyika (26)-inoda kutariswa kuti unzwisise kuzara kwesimba.
(A) Photoexcitation pakurira kuWS2 A-exciton pa2 eV inopinza maerekitironi mubhendi rekuita reWS2. Maburi anoenderana mubhendi revalence reWS2 anozadzwa ipapo ipapo nemaerekitironi kubva kugraphene π-bhendi. (B) Iwo mafotoexcited vatakuri mubhendi rekufambisa reWS2 vane hupenyu hwese ~1 ps. Maburi ari mugraphene π-bhendi anorarama ∼2 ps, zvichiratidza kukosha kwekuwedzera nzira dzekuparadzira dzinoratidzwa nemiseve yakadzvanywa. Mitsetse yakasviba mu (A) uye (B) inoratidza kuchinjika kwebhendi uye shanduko mukugona kwemakemikari. (C) Mumamiriro enguva pfupi, iyo WS2 layer inochajwa zvisina kunaka nepo graphene layer ichichajwa zvakanaka. Pakumhanyisa-selective excitation ine circularly polarized light, maphotoexcited maerekitironi muWS2 uye maburi anoenderana mugraphene anotarisirwa kuratidza zvakapesana spin polarization.
Mumamiriro enguva pfupi, maerekitironi anofara anogara mubhendi rekufambisa reWS2 nepo maburi ephotoexcited ari mu π-bhendi regraphene (Fig. 5C). Izvi zvinoreva kuti WS2 layer yakachajwa zvisina kunaka uye graphene layer inochajwa zvakanaka. Izvi zvinokonzera kushanduka kwepamusoro penguva pfupi (Fig. 2), iyo asymmetry ye graphene pump-probe signal (curves 2 uye 3 yeFig. 3), kusavapo kwemakomba mubhendi yevalence yeWS2 (curve 4 Fig. 3) , pamwe chete nemakomba akawedzerwa mugraphene π-band (Fig. 4). Upenyu hwemamiriro ezvinhu aya-akaparadzaniswa ndeye ~ 1 ps (curve 1 Fig. 3).
Zvakafanana-zvakapatsanurwa-zvakapatsanurwa nyika dzechinyakare dzakaonekwa mune inoenderana van der Waals heterostructures yakagadzirwa kubva maviri akananga-gap semiconductors ane mhando II bhendi kurongeka uye yakadzama bandgap (27-32). Mushure mokunge photoexcitation, ma electrons nemakomba akawanikwa achikurumidza kuenda kuzasi kwebhendi rekufambisa uye kumusoro kwebhendi yevalence, maererano, iyo iri muzvikamu zvakasiyana zveheterostructure (27-32).
Kana iri yedu WS2/graphene heterostructure, nzvimbo ine simba yakanyanya kunaka kune ese maerekitironi nemakomba iri padanho reFermi musimbi yegraphene layer. Naizvozvo, munhu angatarisira kuti ese maerekitironi nemakomba kukurumidza kuendesa kune graphene π-bhendi. Zvisinei, zviyero zvedu zvinoratidza zvakajeka kuti kuendesa gomba (<200 fs) kunonyanya kushanda kupfuura electron transfer (∼1 ps). Isu tinoti izvi kune hukama hune simba hwekurongeka kweWS2 uye mabhendi egraphene sezvakaratidzwa muFig. 1A inopa huwandu hukuru hwematunhu anowanikwa ekupedzisira ekufambiswa kwegomba zvichienzaniswa nekufambiswa kwemagetsi sezvakangotarisirwa ne (14, 15). Muchiitiko chazvino, kutora ~ 2 eV WS2 bandgap, iyo graphene Dirac point uye equilibrium kemikari inogoneka inowanikwa ~ 0.5 uye ~ 0.2 eV pamusoro pepakati peWS2 bandgap, zvichiteerana, kutyora electron-hole symmetry. Isu tinoona kuti huwandu hwenzvimbo dzekupedzisira dziripo dzekuchinjisa gomba ∼ dzakakura zvakapetwa ka6 pane dzekufambisa maelectron (ona Supplementary Materials), ndosaka kuendesa gomba kuchitarisirwa kukurumidza kupfuura kufambisa maerekitironi.
Mufananidzo wakakwana wemicroscopic weinocherechedzwa ultrafast asymmetric charge yekufambisa inofanirwa, zvisinei, zvakare kufunga nezve kupindirana pakati peiyo orbitals inoumba iyo A-exciton wave basa muWS2 uye graphene π-bhendi, zvichiteerana, akasiyana erekitironi uye elekitironi-phonon kupararira. zviteshi zvinosanganisira zvipingamupinyi zvinoiswa nekumhanya, simba, spin, uye pseudospin kuchengetedza, pesvedzero yeplasma. oscillations (33), pamwe chete nebasa rezvinogoneka displacive excitation of coherent phonon oscillations inogona kuyananisira kutamiswa kwechaji (34, 35). Zvakare, munhu anogona kufungidzira kana iyo inocherechedzwa yekuchaja yekufambisa ine maexciton ekuchajisa kana ma electron-hole pairs emahara (ona Zvishandiso Zvekuwedzera). Kumwe kuferefeta kwedzidziso kunodarika chiyero chebepa riripo kunodiwa kujekesa nyaya idzi.
Muchidimbu, takashandisa tr-ARPES kudzidza ultrafast interlayer charge transfer in epitaxial WS2/graphene heterostructure. Takaona kuti, kana tichinakidzwa neresonance kuA-exciton yeWS2 pa2 eV, maburi ephotoexcited anokurumidza kuendesa mugraphene layer apo ma photoexcited electrons anoramba ari muWS2 layer. Isu takati izvi zvakakonzerwa nekuti huwandu hwenzvimbo dzekupedzisira dziripo dzekuchinjisa gomba dzakakura pane dzekufambisa maerekitironi. Hupenyu hwese hwekuchaja-yakapatsanurwa mamiriro enguva pfupi yakawanikwa iine ~ 1 ps. Mukubatana ne spin-selective optical excitation uchishandisa denderedzwa polarized mwenje (22-25), iyo inocherechedzwa yekupedzisira kuchaja yekufambisa inogona kuperekedzwa nekutenderera kuchinjisa. Muchiitiko ichi, iyo yakaferefetwa WS2/graphene heterostructure inogona kushandiswa kushanda zvakanaka optical spin jekiseni mugraphene zvichikonzera novel optospintronic zvishandiso.
Iwo ma graphene samples akakurira pakutengesa semiconducting 6H-SiC(0001) wafers kubva kuSiCrystal GmbH. Iwo maN-doped wafers aive pa-axis aine miscut pazasi 0.5 °. Iyo SiC substrate yaive hydrogen-yakaiswa kuti ibvise makwara uye kuwana yakajairika materrace. Iyo yakachena uye yeatomu yakafuratira Si-terinated surface yakabva yadhirowa nekuisa sampuli muAr atmosphere pa1300 ° C ye8 min (36). Nenzira iyi, isu takawana imwe kabhoni layer apo yega yega yetatu kabhoni atomu yakagadzira covalent bond kune SiC substrate (37). Iyi layer yakabva yashandurwa kuita yakazara sp2-hybridized quasi free-standing gole-doped graphene kuburikidza nehydrogen intercalation (38). Aya masampuli anonzi graphene/H-SiC(0001). Maitiro ese akaitwa mune yekutengesa Black Magic yekukura kamuri kubva kuAixtron. Kukura kweWS2 kwakaitwa mune yakajairwa inopisa-madziro reactor nekudzika-kumanikidza kemikari mhute deposition (39, 40) uchishandisa WO3 uye S hupfu nehupamhi reshiyo ye1:100 se precursors. Iyo WO3 uye S poda yakachengetwa pa900 uye 200 ° C, zvichiteerana. Iyo WO3 powder yakaiswa pedyo ne substrate. Argon yakashandiswa semutakuri gasi nekuyerera kwe8 sccm. Kudzvinyirira mu reactor kwakachengetwa pa 0.5 mbar. Iwo masampuli airatidzwa neyechipiri erekitironi microscopy, atomic simba microscopy, Raman, uye photoluminescence spectroscopy, pamwe neakaderera-simba erekitironi diffraction. Zviyero izvi zvakaratidza mbiri dzakasiyana dzeWS2 single-crystalline domains uko ΓK- kana iyo ΓK'-direction inofambirana neΓK-direction yegraphene layer. Domain side kureba kwakasiyana pakati pe300 ne700 nm, uye iyo yakazara WS2 kufukidzwa yakada kusvika ~40%, yakakodzera kuongororwa kweARPES.
Iyo static ARPES kuyedza yakaitwa nehemispherical analyzer (SPECS PHOIBOS 150) pachishandiswa charge-coupled device-detector system ye-two-dimensional yekuona simba reelectron uye simba. Unpolarized, monochromatic He Iα radiation (21.2 eV) ye-high-flux He discharge source (VG Scienta VUV5000) yakashandiswa kune ese mafotoemission kuyedza. Simba uye kugadziriswa kwemakona muzviedzo zvedu zvaive nani pane 30 meV uye 0.3 ° (inoenderana ne0.01 Å−1), zvichiteerana. Kuedza kwese kwakaitwa patembiricha yemumba. ARPES inzira inotarisisa pamusoro pepamusoro. Kubvisa maphotoelectrons kubva kuWS2 uye graphene layer, samples ine isina kukwana WS2 yekuvhara ~40% yakashandiswa.
Iyo tr-ARPES setup yaive yakavakirwa pa1-kHz Titanium:Sapphire amplifier (Coherent Legend Elite Duo). 2 mJ yesimba rekubuda yakashandiswa kune yakakwira harmonics chizvarwa muargon. Chiedza che ultraviolet chinokonzeresa chakapfuura nepa grating monochromator ichigadzira 100-fs probe pulses pa 26-eV photon simba. 8mJ yeamplifier yekubuda simba yakatumirwa mune optical parametric amplifier (HE-TOPAS kubva kuChiedza Shanduko). Mhepo yechiratidzo pa1-eV photon simba yaive frequency-yakapetwa kaviri mu beta barium borate crystal kuwana iyo 2-eV pombi pulses. Izvo zviyero zve t-ARPES zvakaitwa nehemispherical analyzer (SPECS PHOIBOS 100). Simba rose uye kugadziriswa kwechinguva kwaiva 240 meV uye 200 fs, zvichiteerana.
Zvekuwedzera zvechinyorwa chino zviripo pa http://advances.sciencemag.org/cgi/content/full/6/20/eaay0761/DC1
Ichi chinyorwa chakavhurika chinogoverwa pasi pemitemo yeCreative Commons Attribution-NonCommercial rezinesi, iyo inobvumidza kushandiswa, kugovera, uye kubereka mune chero svikiro, chero mhedzisiro kushandiswa kusiri kwekutengesa bhizimusi uye kana basa rekutanga rakakodzera. quoted.
CHERECHEDZA: Isu tinongokumbira email kero yako kuitira kuti munhu wauri kukurudzira peji azive kuti waida kuti vaione, uye kuti haisi tsamba isina basa. Isu hatitore chero email kero.
Mubvunzo uyu ndewekuongorora kuti uri mushanyi wevanhu here kana kuti kwete uye kudzivirira kutumira spam otomatiki.
NaSven Aeschlimann, Antonio Rossi, Mariana Chávez-Cervantes, Razvan Krause, Benito Arnoldi, Benjamin Stadtmüller, Martin Aeschlimann, Stiven Forti, Filippo Fabbri, Camilla Coletti, Isabella Gierz
Isu tinoratidza ultrafast charge kupatsanurwa muWS2/graphene heterostructure inogona kugonesa optical spin jekiseni mugraphene.
NaSven Aeschlimann, Antonio Rossi, Mariana Chávez-Cervantes, Razvan Krause, Benito Arnoldi, Benjamin Stadtmüller, Martin Aeschlimann, Stiven Forti, Filippo Fabbri, Camilla Coletti, Isabella Gierz
Isu tinoratidza ultrafast charge kupatsanurwa muWS2/graphene heterostructure inogona kugonesa optical spin jekiseni mugraphene.
© 2020 American Association yekufambira mberi kweSainzi. Kodzero dzese dzakachengetwa. AAAS ishamwari yeHINARI, AGORA, OARE, CHORUS, CLOCKSS, CrossRef uye COUNTER.Science Advances ISSN 2375-2548.
Nguva yekutumira: May-25-2020