Nazarin Graphene p-n Junctions ba tare da Lamba ba

Teburin Abubuwan Ciki

1. Gabatarwa

Nazarin graphene ya bayyana fasahar lissafi mai ban sha'awa na barbashi Dirac a cikin shekaru goma da suka wuce. Hanyoyin siffanta na gargajiya suna buƙatar lambobin lantarki waɗanda ke haifar da manyan lahani ciki har da yankuna masu yawan ƙwayoyin cuta kusa da lambobi, p-n junctions marasa so, warwatsewar masu ɗaukar caji, da ragowar juriya daga lithography waɗanda ke rage ingancin na'ura. Waɗannan iyakokin suna da matsala musamman a cikin aikace-aikace kamar graphene spintronics inda lambobi ke rage lokacin rayuwar spin da kuma haifar da hutawa spin.

Wannan bincike ya gabatar da tsarin aunawa ba tare da lamba ba wanda ya shawo kan waɗannan iyakokin ta hanyar haɗa na'urorin graphene a cikin capacitor zuwa da'irori masu resonant na gigahertz (stub tuners). Wannan hanyar tana ba da damar cire duka ƙarfin ƙarfin lantarki na quantum da juriyar kwanciyar hankali na caji ba tare da lambobin lantarki ba, yana ba da hanyar sauri, mai hankali, da kuma siffanta ba tare da kutsawa ba don na'urorin graphene nanocircuits.

2. Tsarin Na'ura

2.1 Ƙirar Da'ira da Kera

Da'irar stub tuner ta ƙunshi layukan watsawa guda biyu (TL1 da TL2) tare da tsayin l da d bi da bi, kowanne kusan λ/4. An tsara da'irar ta amfani da fim ɗin niobium mai kauri 100nm ta hanyar lantarki na lantarki da busasshen sassaƙa tare da Ar/Cl2. Manyan kayan aikin silicon masu juriya tare da babban Layer na SiO2 na 170nm suna rage asarar microwave.

Layin siginar TL1 yana da wata tsagewar ~450nm a kusa da ƙarshen kafin ƙarewa a cikin filin ƙasa. Wannan tsagewar tana aiki azaman mahadar mai mahimmanci don haɗin capacitor tare da na'urar graphene.

2.2 Kulle Graphene da Sanya

Ana kulle graphene mai yawan motsi a cikin boron nitride hexagonal (hBN) ta hanyar canja wuri bushe, wanda ke raba graphene daga rikice-rikicen waje kuma yana ba da damar ƙofar gida. An sanya tarin hBN/graphene/hBN a kan tsagewar ta yadda sassan ɓawon sukan kwanta akan duka layin siginar da filin ƙasa. Sannan an sassaka tarin tare da SF6 a cikin injin sassaƙa mai amsawa don ƙirƙirar geometry rectangular da aka fayyace.

3. Hanyar Aunawa

3.1 Dabarar Resonance na Microwave

Hanyar aunawa ta ƙunshi haɗa na'urorin graphene a cikin capacitor zuwa da'irori masu resonant na superconducting da kuma lura da canje-canje a mitar resonance da faɗin waɗanda suka samo asali daga yanayin caji na ciki na graphene. Wannan hanyar ba tare da lamba ba tana kawar da buƙatar lambobin lantarki yayin samar da babban hankali ga kaddarorin graphene na asali.

3.2 Tsarin Cire Bayanai

Ta hanyar nazarin amsar microwave na da'ira, masu bincike za su iya ƙididdige duka juriyar kwanciyar hankali na caji da ƙarfin lantarki na quantum lokaci guda. Fasahar tana da tasiri musamman don nazarin p-n junctions, waɗanda ke aiki azaman ginin gini na yuwu don na'urorin gani na lantarki.

4. Cikakkun Bayanai na Fasaha

4.1 Tsarin Lissafi

Ƙarfin lantarki na quantum $C_Q$ a cikin graphene ana bayar da shi ta:

$C_Q = \frac{e^2}{\pi} \frac{|E|}{(\hbar v_F)^2}$

inda $e$ ya zama cajin lantarki, $E$ shine makamashi daga batu Dirac, $\hbar$ shine rage madaidaicin Planck, kuma $v_F$ shine saurin Fermi.

Juriya na kwanciyar hankali na caji $R_q$ yana bin dangantaka:

$R_q = \frac{h}{2e^2} \approx 12.9\,k\Omega$

don tashar quantum guda ɗaya, inda $h$ ya zama madaidaicin Planck.

4.2 Nazarin Da'ira Mai Daidai

Da'irar daidai ta ƙunshi abubuwa masu ƙima waɗanda ke wakiltar:

• Ƙarfin lantarki na quantum $C_{Q1}$ da $C_{Q2}$
• Ƙarfin lantarki na ƙofa $C_{G1}$ da $C_{G2}$
• Juriya na kwanciyar hankali na caji $R_1$ da $R_2$
• Ƙarfin lantarki na tsagewa $C_{slit}$
• Ƙarfin lantarki na yanki $C_{12}$ da juriya $R_{12}$

5. Sakamakon Gwaji

5.1 Nazarin Amsar Resonance

Amsar microwave tana nuna bayyanannun canje-canje a mitar resonance da faɗi lokacin da aka kafa p-n junctions na graphene. Waɗannan canje-canjen suna da alaƙa kai tsaye tare da yanayin caji na ciki da yawan jihohi a cikin graphene, yana ba da damar cire mahimman sigogi ba tare da kayan aikin lamba ba.

5.2 Siffanta p-n Junction

Ta hanyar kafa p-n junctions ta hanyar ƙofar gida, masu bincike sun bincika yanayin caji na ciki na da'irori na graphene. Ma'aunin ba tare da lamba ba ya bayyana cikakkun bayanai game da rarraba masu ɗauka da kaddarorin sufuri a kan mahadar mahadar, yana nuna hankalin dabarar ga canje-canjen lantarki masu zurfi.

6. Aiwar Code

A ƙasa akwai misalin pseudocode na Python don nazarin bayanan resonance:

import numpy as np
import matplotlib.pyplot as plt
from scipy.optimize import curve_fit

def resonance_model(f, f0, Q, A, phi):
    """Samfurin Lorentzian don lanƙwasa resonance"""
    return A * (Q**2 / ((f/f0 - 1)**2 + Q**2)) * np.cos(phi)

def extract_graphene_parameters(frequency, amplitude):
    """Cire sigogin graphene daga bayanan resonance"""
    # Hasashen farko don sigogi
    p0 = [frequency[np.argmax(amplitude)], 1000, max(amplitude), 0]
    
    # Dacewa da lanƙwasa resonance
    popt, pcov = curve_fit(resonance_model, frequency, amplitude, p0=p0)
    f0, Q, A, phi = popt
    
    # Ƙididdige ƙarfin lantarki na quantum da juriyar kwanciyar hankali
    delta_f = f0 - baseline_frequency
    C_q = calculate_quantum_capacitance(delta_f, geometric_capacitance)
    R_q = calculate_relaxation_resistance(Q, f0, C_q)
    
    return C_q, R_q, popt

def calculate_quantum_capacitance(delta_f, C_geo):
    """Ƙididdige ƙarfin lantarki na quantum daga canjin mitar"""
    return -C_geo * (delta_f / f0)

def calculate_relaxation_resistance(Q, f0, C_q):
    """Ƙididdige juriyar kwanciyar hankali na caji daga ingancin inganci"""
    return 1 / (2 * np.pi * f0 * C_q * Q)

7. Aikace-aikace da Hanyoyin Gaba

Aikace-aikace na Kusa:

• Kula da inganci a cikin kera na'urar graphene
• Siffanta tsarin kayan 2D masu hankali
• Nazarin tasirin Hall na quantum ba tare da kayan aikin lamba ba
• Binciken jihohin lantarki masu alaƙa a cikin graphene bilayer mai karkatarwa

Hanyoyin Bincike na Gaba:

• Haɗawa tare da dandamali na lissafi na quantum mai sanyaya
• Ƙaddamarwa zuwa wasu kayan 2D (MoS2, WSe2, da sauransu)
• Haɓaka dabarun siffanta mitar da yawa
• Aikace-aikace ga tsarin na'urori masu ƙididdigewa
• Rage girman don aikace-aikacen hankali na quantum akan guntu

8. Nazari na Asali

Wannan bincike yana wakiltar ci gaba mai mahimmanci a cikin hanyar siffanta kayan 2D. Hanyar ba tare da lamba ba tana magance iyakoki na asali waɗanda suka addabi binciken graphene tun lokacin da aka keɓe shi a cikin 2004. Ma'aunin lantarki na gargajiya, yayin da yake da daraja, dole ne ya canza kaddarorin da suke neman aunawa ta hanyar haifar da ƙwayoyin cuta na lamba, warwatsewa, da jihohin mahadar. An ga irin waɗannan ƙalubalen a cikin wasu tsarin kayan nano, inda kayan aunawa ke tasiri tsarin da ake nazarin—wata matsala ta asali a ka'idar aunawa ta quantum.

Ƙarfin dabarar na cire duka ƙarfin lantarki na quantum da juriyar kwanciyar hankali na caji lokaci guda yana da ban sha'awa musamman. Ƙarfin lantarki na quantum, wanda ya zama mahimmanci a cikin tsarin ƙananan girma inda yawan jihohi ya yi ƙanƙanta, yana ba da haske kai tsaye ga tsarin band ɗin lantarki. Kamar yadda aka nuna a cikin binciken Cibiyar Ƙididdiga ta Ƙasa (NIST) akan ma'aunin lantarki na quantum, madaidaicin ma'aunin ƙarfin lantarki yana da mahimmanci don haɓaka ma'aunin lantarki na tushen quantum. Juriya na kwanciyar hankali na caji da aka ciro na kusan $h/2e^2$ kowace tashar quantum ya yi daidai da hasashen ka'idar don tsarin mesoscopic, daidai da binciken daga Jami'ar Delft kan lambobin tashar quantum.

Idan aka kwatanta da madadin dabarun ba tare da lamba ba kamar binciken terahertz ko microscopy na juriya na microwave, wannan hanyar tana ba da mafi girman hankali ga yanayin caji na ciki yayin kiyaye halayen da ba na kutsawa ba. Amfani da da'irori masu resonant na superconducting yana ba da mahimman abubuwan inganci don madaidaicin ma'auni, kama da hanyoyin da ake amfani da su a cikin gwaje-gwajen lantarki na lantarki na quantum (cQED) tare da qubits masu superconducting. Hanyar tana raba kamanceceniya ta ra'ayi tare da ma'aunin ƙarfin lantarki na quantum da ake amfani da su a cikin transistors na lantarki guda ɗaya na tushen graphene, amma yana ƙaddamar da waɗannan ra'ayoyin zuwa gaɓoɓin na'ura masu sarƙaƙƙiya kamar p-n junctions.

Tasirin ga na'urorin lantarki na graphene yana da girma. Kamar yadda aka lura a cikin nazarin Fasahar MIT na kasuwancin kayan 2D, juriya na lamba ya kasance babban toshewa a cikin aikin na'urar graphene. Wannan dabarar na iya haɓaka ingantaccen na'ura ta hanyar ba da damar sauri, lalata siffanta yayin kera. Bugu da ƙari, ikon nazarin p-n junctions ba tare da kayan aikin lamba ba yana da mahimmanci don haɓaka na'urorin gani na lantarki na tushen graphene, inda daidaitaccen sarrafa hanyoyin masu ɗauka yake da mahimmanci—wani yanki da ake bincike a hukumance a cibiyoyi kamar Cibiyar Graphene ta Ƙasa ta Jami'ar Manchester.

Idan muka duba gaba, ana iya haɗa wannan hanyar tare da hanyoyin koyon inji don siffanta na'ura ta atomatik, kama da dabarun da ake haɓakawa a Jami'ar Stanford don binciken kayan aiki mai yawa. Ƙa'idodin da aka nuna anan kuma na iya samun aikace-aikace a kimiyyar bayanai na quantum, musamman don siffanta mahadar kayan aiki a cikin na'urori masu sarrafa quantum na superconducting, inda asarar mahadar ke tasiri lokacin haɗin kai na qubit.

9. Nassoshi

1. Novoselov, K. S., et al. "Tasirin filin lantarki a cikin fina-finai carbon na atomically bakin ciki." Kimiyya 306.5696 (2004): 666-669.
2. Dean, C. R., et al. "Kayan aikin boron nitride don ingantaccen lantarki na graphene." Nanotechnology na Halitta 5.10 (2010): 722-726.
3. Datta, S. "Jigilar lantarki a cikin tsarin mesoscopic." Mujallar Jami'ar Cambridge (1997).
4. Piot, B. A., et al. "Aunawar ɓarna a cikin na'urar kallo na quantum Hall na graphene." Mujallar Physical Review 118.16 (2017): 166803.
5. Cibiyar Ƙididdiga ta Ƙasa. "Ma'aunin Lantarki na Quantum." NIST Takamaiman Bugawa (2019).
6. Jami'ar Delft. "Binciken Physics na Mesoscopic." TU Delft Publications (2020).
7. Jami'ar Manchester. "Rahotannin Fasaha na Cibiyar Graphene ta Ƙasa." (2021).
8. Jami'ar Stanford. "Koyon Injini don Gano Kayayyaki." Nature Reviews Materials 5.5 (2020): 295-296.
9. MIT Technology Review. "Kasuwancin Kayan 2D." (2022).