@article {1439,
	title = {Quantum size effects on the work function of metallic thin film nanostructures},
	journal = {Proceedings of the National Academy of Sciences of the United States of America},
	volume = {107},
	number = {29},
	year = {2010},
	note = {<p>ISI Document Delivery No.: 628TJTimes Cited: 4Cited Reference Count: 21Cited References:      Miller T, 2009, PHYS REV LETT, V102     Qin SY, 2009, SCIENCE, V324, P1314     Liu X, 2008, APPL PHYS LETT, V93     Ozer MM, 2007, SCIENCE, V316, P1594, DOI 10.1126/science.1142159     Ma XC, 2007, P NATL ACAD SCI USA, V104, P9204, DOI 10.1073/pnas.0611024104     Qi Y, 2007, APPL PHYS LETT, V90     Ozer MM, 2006, NAT PHYS, V2, P173, DOI 10.1038/nphys244     Eom D, 2006, PHYS REV LETT, V96, DOI 10.1103/PhysRevLett.96.027005     JIA Y, 2006, PHYS REV B, V74, DOI 10.1103/PhysRevB.74.035433     Czoschke P, 2004, PHYS REV LETT, V93, DOI 10.1103/PhysRevLett.93.036103     Paggel JJ, 2002, PHYS REV B, V66, DOI 10.1103/PhysRevB.66.233403     Wei CM, 2002, PHYS REV B, V66, DOI 10.1103/PhysRevB.66.233408     CHANG SH, 2002, PHYS REV B, V66     HUPALO M, 2002, PHYS REV B, V66, DOI 10.1103/PhysRevB.66.161410     Su WB, 2001, PHYS REV LETT, V86, P5116, DOI 10.1103/PhysRevLett.86.5116     Luh DA, 2001, SCIENCE, V292, P1131, DOI 10.1126/science.292.5519.1131     Yeh V, 2000, PHYS REV LETT, V85, P5158, DOI 10.1103/PhysRevLett.85.5158     Zhang ZY, 1998, PHYS REV LETT, V80, P5381, DOI 10.1103/PhysRevLett.80.5381     Smith AR, 1996, SCIENCE, V273, P226, DOI 10.1126/science.273.5272.226     STROSCIO JA, 1986, PHYS REV LETT, V57, P2579, DOI 10.1103/PhysRevLett.57.2579     SCHULTE FK, 1976, SURF SCI, V55, P427, DOI 10.1016/0039-6028(76)90250-8Kim, Jungdae Qin, Shengyong Yao, Wang Niu, Qian Chou, M. Y. Shih, Chih-KangNSF[DMR-0906025, CMMI-0928664]; Welch Foundation[F-1672]; Texas Advanced Research Program[003658-0037-2007]; DOE[DE-FG02-97ER45632]This work was supported by NSF Grant DMR-0906025, CMMI-0928664, Welch Foundation F-1672, and Texas Advanced Research Program 003658-0037-2007. M.-Y.C. acknowledges support by DOE Grant DE-FG02-97ER45632.NATL ACAD SCIENCESWASHINGTON</p>
},
	month = {Jul},
	pages = {12761-12765},
	type = {Article},
	abstract = {<p>In this paper, we present the direct observation of quantum size effects (QSE) on the work function in ultrathin Pb films. By using scanning tunneling microscopy and spectroscopy, we show that the very existence of quantum well states (QWS) in these ultrathin films profoundly affects the measured tunneling decay constant kappa, resulting in a very rich phenomenon of "quantum oscillations" in kappa as a function of thickness, L, and bias voltage, V(s). More specifically, we find that the phase of the quantum oscillations in kappa vs. L depends sensitively upon the bias voltage, which often results in a total phase reversal at different biases. On the other hand, at very low sample bias (vertical bar V(s)vertical bar \&lt; 0.03 V) the measurement of kappa vs. L accurately reflects the quantum size effect on the work function. In particular, the minima in the quantum oscillations of kappa vs. L occur at the locations where QWS cross the Fermi energy, thus directly unraveling the QSE on the work function in ultrathin films, which was predicted more than three decades ago. This further clarifies several contradictions regarding the relationship between the QWS locations and the work function.</p>
},
	keywords = {PB, quantum well states, STABILITY, STM, SUPERCONDUCTIVITY, SURFACE},
	isbn = {0027-8424},
	url = {<Go to ISI>://WOS:000280144500012},
	author = {Kim, J. and Qin, S. Y. and Yao, W. and Niu, Q. and Chou, M. Y. and Shih, C. K.}
}
