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Volumn 81, Issue 4, 2010, Pages

Decoherence of spin qubits due to a nearby charge fluctuator in gate-defined double dots

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EID: 77954828730     PISSN: 10980121     EISSN: 1550235X     Source Type: Journal    
DOI: 10.1103/PhysRevB.81.045304     Document Type: Article
Times cited : (50)

References (64)
  • 6
    • 77954825108 scopus 로고    scopus 로고
    • (private communication).
    • Amir Yacoby (private communication).
    • Yacoby, A.1
  • 7
    • 0037162826 scopus 로고    scopus 로고
    • Current rectification by Pauli exclusion in a weakly coupled double quantum dot system
    • DOI 10.1126/science.1070958
    • K. Ono, D. G. Austing, Y. Tokura, and S. Tarucha, Science 297, 1313 (2002). 10.1126/science.1070958 (Pubitemid 34918615)
    • (2002) Science , vol.297 , Issue.5585 , pp. 1313-1317
    • Ono, K.1    Austing, D.G.2    Tokura, Y.3    Tarucha, S.4
  • 11
    • 36749066659 scopus 로고    scopus 로고
    • Coherent control of a single electron spin with electric fields
    • DOI 10.1126/science.1148092
    • K. C. Nowack, F. H. L. Koppens, Yu. V. Nazarov, and L. M. K. Vandersypen, Science 318, 1430 (2007). 10.1126/science.1148092 (Pubitemid 350208949)
    • (2007) Science , vol.318 , Issue.5855 , pp. 1430-1433
    • Nowack, K.C.1    Koppens, F.H.L.2    Nazarov, Yu.V.3    Vandersypen, L.M.K.4
  • 17
    • 34548387985 scopus 로고    scopus 로고
    • Large nuclear overhauser fields detected in vertically coupled double quantum dots
    • DOI 10.1103/PhysRevLett.99.096804
    • J. Baugh, Y. Kitamura, K. Ono, and S. Tarucha, Phys. Rev. Lett. 99, 096804 (2007). 10.1103/PhysRevLett.99.096804 (Pubitemid 47358530)
    • (2007) Physical Review Letters , vol.99 , Issue.9 , pp. 096804
    • Baugh, J.1    Kitamura, Y.2    Ono, K.3    Tarucha, S.4
  • 21
    • 33846975100 scopus 로고    scopus 로고
    • 10.1103/PhysRevLett.98.077602
    • W. Yao, R. B. Liu, and L. J. Sham, Phys. Rev. Lett. 98, 077602 (2007). 10.1103/PhysRevLett.98.077602
    • (2007) Phys. Rev. Lett. , vol.98 , pp. 077602
    • Yao, W.1    Liu, R.B.2    Sham, L.J.3
  • 22
    • 50449092153 scopus 로고    scopus 로고
    • 10.1103/PhysRevB.78.085315;
    • W. Yang and R-B. Liu, Phys. Rev. B 78, 085315 (2008) 10.1103/PhysRevB.78. 085315
    • (2008) Phys. Rev. B , vol.78 , pp. 085315
    • Yang, W.1    Liu, R.-B.2
  • 23
    • 65149105211 scopus 로고    scopus 로고
    • 10.1103/PhysRevB.79.115320
    • W. Yang and R-B. Liu, Phys. Rev. B 79, 115320 (2009). 10.1103/PhysRevB.79.115320
    • (2009) Phys. Rev. B , vol.79 , pp. 115320
    • Yang, W.1    Liu, R.-B.2
  • 24
    • 37249000852 scopus 로고    scopus 로고
    • 10.1103/PhysRevB.76.241303
    • W. M. Witzel, and S. Das Sarma, Phys. Rev. B 76, 241303 (R) (2007). 10.1103/PhysRevB.76.241303
    • (2007) Phys. Rev. B , vol.76 , pp. 241303
    • Witzel, W.M.1    Das Sarma, S.2
  • 26
    • 29644439946 scopus 로고    scopus 로고
    • 10.1103/PhysRevB.72.165333;
    • C. Deng and X. Hu, Phys. Rev. B 72, 165333 (2005) 10.1103/PhysRevB.72. 165333
    • (2005) Phys. Rev. B , vol.72 , pp. 165333
    • Deng, C.1    Hu, X.2
  • 30
    • 14044268751 scopus 로고    scopus 로고
    • Spin quantum computation in silicon nanostructures
    • DOI 10.1016/j.ssc.2004.12.037, PII S0038109804011007
    • S. Das Sarma, R. de Sousa, X. Hu, and B. Koiller, Solid State Commun. 133, 737 (2005). 10.1016/j.ssc.2004.12.037 (Pubitemid 40276677)
    • (2005) Solid State Communications , vol.133 , Issue.SPEC. ISS. , pp. 737-746
    • Sarma, S.D.1    Sousa, R.D.2    Hu, X.3    Koiller, B.4
  • 31
    • 34047269788 scopus 로고    scopus 로고
    • 10.1103/PhysRevB.75.161301
    • G. Ramon and X. Hu, Phys. Rev. B 75, 161301 (R) (2007). 10.1103/PhysRevB.75.161301
    • (2007) Phys. Rev. B , vol.75 , pp. 161301
    • Ramon, G.1    Hu, X.2
  • 35
    • 33644881622 scopus 로고    scopus 로고
    • 10.1103/PhysRevLett.96.100501
    • X. Hu and S. Das Sarma, Phys. Rev. Lett. 96, 100501 (2006). 10.1103/PhysRevLett.96.100501
    • (2006) Phys. Rev. Lett. , vol.96 , pp. 100501
    • Hu, X.1    Das Sarma, S.2
  • 42
    • 77954734099 scopus 로고    scopus 로고
    • 10.1103/PhysRevB.80.195315
    • K. Roszak and P. Machnikowski, Phys. Rev. B 80, 195315 (2009). 10.1103/PhysRevB.80.195315
    • (2009) Phys. Rev. B , vol.80 , pp. 195315
    • Roszak, K.1    MacHnikowski, P.2
  • 43
    • 77954830152 scopus 로고    scopus 로고
    • arXiv:0903.1080 (unpublished).
    • X. Hu, arXiv:0903.1080 (unpublished).
    • Hu, X.1
  • 47
    • 18144385479 scopus 로고    scopus 로고
    • Low- And high-frequency noise from coherent two-level systems
    • DOI 10.1103/PhysRevLett.94.127002, 127002
    • A. Shnirman, G. Schön, I. Martin, and Y. Makhlin, Phys. Rev. Lett. 94, 127002 (2005). 10.1103/PhysRevLett.94.127002 (Pubitemid 40620571)
    • (2005) Physical Review Letters , vol.94 , Issue.12 , pp. 1-4
    • Shnirman, A.1    Schon, G.2    Martin, I.3    Makhlin, Y.4
  • 51
    • 27144540078 scopus 로고    scopus 로고
    • Models of environment and T1 relaxation in Josephson charge qubits
    • DOI 10.1103/PhysRevLett.95.046805, 046805
    • L. Faoro, J. Bergli, B. L. Altshuler, and Y. M. Galperin, Phys. Rev. Lett. 95, 046805 (2005). 10.1103/PhysRevLett.95.046805 (Pubitemid 41506236)
    • (2005) Physical Review Letters , vol.95 , Issue.4 , pp. 1-4
    • Faoro, L.1    Bergli, J.2    Altshuler, B.L.3    Galperin, Y.M.4
  • 52
    • 77954822403 scopus 로고    scopus 로고
    • We excluded a constant term that does not play any role in the system dynamics.
    • We excluded a constant term that does not play any role in the system dynamics.
  • 53
    • 77954829274 scopus 로고    scopus 로고
    • arXiv:0909.4116 (unpublished).
    • Guy Ramon and Xuedong Hu, arXiv:0909.4116 (unpublished).
    • Ramon, G.1    Hu, X.2
  • 54
    • 77954825555 scopus 로고    scopus 로고
    • We do not expect that a choice of a spheical symmetric TLS wavefunction will induce any qualitative change in our results.
    • We do not expect that a choice of a spheical symmetric TLS wavefunction will induce any qualitative change in our results.
  • 55
    • 77954829486 scopus 로고    scopus 로고
    • When tunneling between the TLS centers is introduced the TLS eigenstates become (L±R ) /√2 (for ωT =0) and contributions from off-diagonal TLS states become appreciable. The qubit-TLS coupling then produces additional terms in the interaction Hamiltonian (Eq. ) of the form σxT ⊗- σzQ, σxT ⊗- IQ. Assuming the TLS is unbiased there is no TLS dipole term and the leading contribution comes from the TLS quadrupole term, which is calculated to be very small for the TLS tunneling values assumed in this paper.
    • When tunneling between the TLS centers is introduced the TLS eigenstates become (L ± R) / √ 2 (for ω T = 0) and contributions from off-diagonal TLS states become appreciable. The qubit-TLS coupling then produces additional terms in the interaction Hamiltonian (Eq.) of the form σ x T ⊗- σ z Q, σ x T ⊗- I Q. Assuming the TLS is unbiased there is no TLS dipole term and the leading contribution comes from the TLS quadrupole term, which is calculated to be very small for the TLS tunneling values assumed in this paper.
  • 58
    • 33846656370 scopus 로고    scopus 로고
    • Universal set of quantum gates for double-dot spin qubits with fixed interdot coupling
    • DOI 10.1103/PhysRevLett.98.050502
    • R. Hanson and G. Burkard, Phys. Rev. Lett. 98, 050502 (2007). 10.1103/PhysRevLett.98.050502 (Pubitemid 46198306)
    • (2007) Physical Review Letters , vol.98 , Issue.5 , pp. 050502
    • Hanson, R.1    Burkard, G.2
  • 59
    • 77954827613 scopus 로고    scopus 로고
    • We have verified that switching times ≲1ns, comparable to experimentally used bias sweep times, do not contribute appreciably to gate errors in most cases, and in any case can be corrected by a careful pulse design. To isolate the effects of qubit-TLS coupling we have nevertheless considered very short switching times (∼1ps ).
    • We have verified that switching times ≲ 1ns, comparable to experimentally used bias sweep times, do not contribute appreciably to gate errors in most cases, and in any case can be corrected by a careful pulse design. To isolate the effects of qubit-TLS coupling we have nevertheless considered very short switching times (∼ 1ps).
  • 60
    • 77954821197 scopus 로고    scopus 로고
    • Throughout most of the parameter ranges presented in Figure 7, tT >Γ thus the TLS is not overdamped exclugin a direct coupling of its reservoir to the qubit.
    • Throughout most of the parameter ranges presented in Figure 7, t T > Γ thus the TLS is not overdamped exclugin a direct coupling of its reservoir to the qubit.
  • 61
    • 77954831262 scopus 로고    scopus 로고
    • Higher order contributions to β in the multipole expansion may have an opposite sign to that of the leading term. Typically, their magnitude will be comparable at shorter distances (R≲25nm ), where the expansion converges slowly and yet higher order contributions are needed for an accurate estimate of the coupling.
    • Higher order contributions to β in the multipole expansion may have an opposite sign to that of the leading term. Typically, their magnitude will be comparable at shorter distances (R ≲ 25 nm), where the expansion converges slowly and yet higher order contributions are needed for an accurate estimate of the coupling.
  • 62
    • 77954829627 scopus 로고    scopus 로고
    • The geometry depicted in Fig. yields β/γ∼1 and thus yields considerably larger gate errors and dephsing as compared with the parallel-axis geometry.
    • The geometry depicted in Fig. yields β / γ ∼ 1 and thus yields considerably larger gate errors and dephsing as compared with the parallel-axis geometry.
  • 63
    • 77954821013 scopus 로고    scopus 로고
    • In refering to the double dot bias we adopt the convention of zero bias at the anticrossing point.
    • In refering to the double dot bias we adopt the convention of zero bias at the anticrossing point.
  • 64
    • 77954822769 scopus 로고    scopus 로고
    • Notice that while the qubit holds two electrons, its charge density corresponds to single-particle operators. The two-particle qubit states are considered at a later stage, when evaluating the Coulomb matrix elements, Eq. .
    • Notice that while the qubit holds two electrons, its charge density corresponds to single-particle operators. The two-particle qubit states are considered at a later stage, when evaluating the Coulomb matrix elements, Eq.


* 이 정보는 Elsevier사의 SCOPUS DB에서 KISTI가 분석하여 추출한 것입니다.