We present experimental studies of the current pumped through a dynamic quantum dot over a wide range of magnetic fields. At low fields we observe a repeatable structure indicating increased confinement of the electrons in the dynamic dot. At higher fields (), we observe a structure which changes markedly from device to device suggesting that in this regime the transport is sensitive to local disorder. The results are significant for the development of dynamic quantum dot pumps as quantum standards of electrical current.
REFERENCES
1.
M. J. T.
Milton
, J. M.
Williams
, and S. J.
Bennett
, Metrologia
44
, 356
(2007
).2.
M. W.
Keller
, J. M.
Martinis
, N. M.
Zimmerman
, and A. H.
Steinbach
, Appl. Phys. Lett.
69
, 1804
(1996
).3.
V. F.
Maisi
, Yu. A.
Pashkin
, S.
Kafanov
, J. S.
Tsai
, and J. P.
Pekola
, New J. Phys.
11
, 113057
(2009
).4.
M. D.
Blumenthal
, B.
Kaestner
, L.
Li
, S.
Giblin
, T. J. B. M.
Janssen
, M.
Pepper
, D.
Anderson
, G.
Jones
, and D. A.
Ritchie
, Nat. Phys.
3
, 343
(2007
).5.
J. M.
Shilton
, V. I.
Talyanskii
, M.
Pepper
, D. A.
Ritchie
, J. E. F.
Frost
, C. J. B.
Ford
, C. G.
Smith
, and G. A. C.
Jones
, J. Phys.: Condens. Matter
8
, L531
(1996
).6.
M.
Kataoka
, M. R.
Astley
, A. L.
Thorn
, D. K. L.
Oi
, C. H. W.
Barnes
, C. J. B.
Ford
, D.
Anderson
, G. A. C.
Jones
, I.
Farrer
, D. A.
Ritchie
, and M.
Pepper
, Phys. Rev. Lett.
, 102
, 156801
(2009
).7.
R. J.
Schneble
, M.
Kataoka
, C. J. B.
Ford
, C. H. W.
Barnes
, D.
Anderson
, G. A. C.
Jones
, I.
Farrer
, D. A.
Ritchie
, and M.
Pepper
, Appl. Phys. Lett.
89
, 122104
(2006
).8.
S. J.
Wright
, M. D.
Blumenthal
, G.
Gumbs
, A. L.
Thorn
, M.
Pepper
, T. J. B. M.
Janssen
, S. N.
Holmes
, D.
Anderson
, G. A. C.
Jones
, C. A.
Nicoll
, and D. A.
Ritchie
, Phys. Rev. B
78
, 233311
(2008
).9.
S. J.
Wright
, M. D.
Blumenthal
, M.
Pepper
, D.
Anderson
, G. A. C.
Jones
, C. A.
Nicoll
, and D. A.
Ritchie
, Phys. Rev. B
80
, 113303
(2009
).10.
T. J. B. M.
Janssen
and A.
Hartland
, IEE Proc.:Sci., Meas. Technol.
147
, 174
(2000
).11.
R. C.
Ashoori
, H. L.
Stormer
, J. S.
Weiner
, L. N.
Pfeiffer
, S. J.
Pearton
, K. W.
Baldwin
, and K. W.
West
, Phys. Rev. Lett.
68
, 3088
(1992
).12.
N. B.
Zhitenev
, R. C.
Ashoori
, L. N.
Pfeiffer
, and K. W.
West
, Phys. Rev. Lett.
79
, 2308
(1997
).13.
B.
Kaestner
, C.
Leicht
, V.
Kashcheyevs
, K.
Pierz
, U.
Siegner
, and H. W.
Schumacher
, Appl. Phys. Lett.
94
, 012106
(2009
).14.
S. P.
Giblin
, S. J.
Wright
, J.
Fletcher
, M.
Kataoka
, M.
Pepper
, T. J. B. M.
Janssen
, D. A.
Ritchie
, C. A.
Nicoll
, D.
Anderson
, and G. A. C.
Jones
, New J. Phys.
12
, 073013
(2010
).15.
We note that the transition corresponding to the green dashed line in Fig. 2 also shifts in Vent, contributing to a narrowing of the ne=nc plateaus. This shift can be explained by a less negative Fermi energy in the quasi-1D channel as we increase the magnetic field. This is expected to arise as a result of the magnetic depopulation of the wire. The narrowing of the ne=nc plateaus does not appear to lead to a reduction in the degree of current quantization, as can be seen by the high resolution measurements of Ref. 14.
16.
A full explanation of the evolution of the pump map in a magnetic field will require a more detailed computational study of electron dynamics in this device. The manuscript is in preparation.
17.
B.
Kaestner
, V.
Kashcheyevs
, S.
Amakawa
, M. D.
Blumenthal
, L.
Li
, T. J. B. M.
Janssen
, G.
Hein
, K.
Pierz
, T.
Weimann
, U.
Siegner
, and H. W.
Schumacher
, Phys. Rev. B
77
, 153301
(2008
).18.
B.
Kaestner
, V.
Kashcheyevs
, G.
Hein
, K.
Pierz
, U.
Siegner
, and H. W.
Schumacher
, Appl. Phys. Lett.
92
, 192106
(2008
).19.
V.
Kashcheyevs
and B.
Kaestner
, Phys. Rev. Lett.
104
, 186805
(2010
).20.
Yi
Wan
, Gerardo
Ortiz
, and P.
Phillips
, Phys. Rev. Lett.
75
2879
(1995
).21.
M. E.
Raikh
, L. I.
Glazman
, and L. E.
Zhukov
, Phys. Rev. Lett.
77
, 1354
(1996
).22.
C. M.
Canali
, Phys. Rev. Lett.
84
, 3934
(2000
).23.
M.
Brodsky
, N. B.
Zhitenev
, R. C.
Ashoori
, L. N.
Pfeiffer
, and K. W.
West
, Phys. Rev. Lett.
85
, 2356
(2000
).24.
M.
Pepper
, J. of Non-Cryst. Solids
32
, 161
(1979
).© 2011 American Institute of Physics.
2011
American Institute of Physics
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