DEPHASING OF QD EXCITON ORBITAL AND SPIN STATES DUE TO HYBRIDIZATION WITH BULK COLLECTIVE EXCITATIONS

2011 ◽  
Vol 25 (10) ◽  
pp. 1359-1375
Author(s):  
W. JACAK ◽  
J. KRASNYJ ◽  
L. JACAK ◽  
W. DONDEROWICZ
Keyword(s):  
Quantum Dot ◽  
Degrees Of Freedom ◽  
Magnetic Semiconductor ◽  
General Rule ◽  
Exciton State ◽  
Spin States ◽  
Spin Dephasing ◽  
Pure Dephasing ◽  
Significant Difference ◽  
Green Function Approach

We analyze theoretically a hybridization type dressing of orbital (i.e., charge) and spin degrees of freedom of excitations captured in semiconductor quantum dot with band phonons and magnons (the latter for magnetic semiconductor surroundings), as a mechanism of dephasing of rapidly excited dot exciton state. Within the Green function approach we derive our previously formulated heuristic general rule for estimation of corresponding dephasing time-rate. The pure dephasing (off-diagonal decoherence) of quantum dot exciton resulting due to this dressing is studied, for both orbital and spin states of the exciton. A significant difference between phonon-induced (for charge) and magnon-assisted (for spin) quantum dot exciton dephasing is indicated as the result of the spin conservation, which leads to the disappearance of the exciton spin pure-dephasing at T = 0 (freezing out of spin dephasing), in contrary to the exciton charge dephasing caused by phonons, which maintains strong even at T = 0.

SPIN-DEPHASING ON A QUANTUM DOT WITH A NEARBY QUANTUM POINT CONTACT

2009 ◽  
Vol 23 (04) ◽  
pp. 623-631
Author(s):  
FEI-YUN ZHU ◽  
TAO TU ◽  
GUO-PING GUO
Keyword(s):  
Quantum Dot ◽  
Transition Rate ◽  
Point Contact ◽  
Quantum Point Contact ◽  
Spin States ◽  
Quantum Zeno Effect ◽  
Spin Dephasing ◽  
Zeno Effect ◽  
Spin Decoherence ◽  
Quantum Point

We study the evolution behaviors of an electron spin on a quantum dot due to coupling to a nearby quantum point contact (QPC) as a measurement device. We obtain the dephasing time T2 of about 100 ns when the spin decoherence is only induced by the QPC. We also find that the repeated QPC measurement will slow down the transition rate between spin states which can be interpreted in terms of the quantum Zeno effect.

scholarly journals Two-photon interference from a quantum dot microcavity: Persistent pure dephasing and suppression of time jitter

2015 ◽  
Vol 91 (7) ◽  
Author(s):  
Sebastian Unsleber ◽  
Dara P. S. McCutcheon ◽  
Michael Dambach ◽  
Matthias Lermer ◽  
Niels Gregersen ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Time Jitter ◽  
Two Photon ◽  
Pure Dephasing

scholarly journals Measurement of the inhomogeneous broadening of a bi-exciton state in a quantum dot using Franson-type nonlocal interference

2017 ◽  
Vol 25 (3) ◽  
pp. 1778 ◽  
Author(s):  
Yong-Nan Sun ◽  
Yang Zou ◽  
Geng Chen ◽  
Jian-Shun Tang ◽  
Hai-Qiao Ni ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Exciton State ◽  
Inhomogeneous Broadening

scholarly journals EFEKTIFITAS METODE MENGAJAR KESELURUHAN DENGAN METODE MENGAJAR BAGIAN PERBAGIAN TERHADAP HASIL BELAJAR MENGUMPAN (PASSING) KAKI BAGIAN DALAM PADA PERMAINAN FUTSAL MAHASISWA FIK UNM

2020 ◽  
Vol 12 (1) ◽  
pp. 48
Author(s):  
Sudirman Sudirman ◽  
Andi Mas Jaya
Keyword(s):  
Experimental Method ◽  
Learning Outcomes ◽  
Degrees Of Freedom ◽  
Teaching Method ◽  
Treatment Method ◽  
T Test ◽  
Analysis Technique ◽  
Significant Difference ◽  
Before And After

This study aims to find out which is more effective between the overall method and the teaching method part by section on learning outcomes passing (passing) the inner leg in students who take Futsal learning. This research was carried out by an experimental method in total sampling. Thedata analysis technique used to test the hypothesis is the t-test, at a significant level α= 0.05, starting with calculating the t-count value to compare with the t-table value at a significant level of 95%. (1) The whole method is obtained by t-count = 4, the value listed in t-table with degrees of freedom (dk) = 15-1 = 14. A significant level of 5% is 2.14, so t-count> t-table, means that there is a convincing (significant) difference before and after being given the overall method treatment. (2) The teaching method part of division is obtained the value of t-count = 3.7, the value listed in t-table with degrees of freedom (dk) = 15-1 = 14. Significant level of 5% is 2.14, so t-count> t-table, means that there is a convincing (significant) difference before and after the treatment method is given in part. And (3) The overall method and the part-by-part teaching method obtained t-count = 3.2, the values listed in t-table with degrees of freedom (dk) = 15 + 15-2 = 28. A significant level of 5% is 2.05. So t-count> t-table.

scholarly journals Pengembangan Lembar Kegiatan Siswa (LKS) Berbasis Inkuiri Terbimbing Pada Materi Teks Diskusi Siswa SMP Kelas IX

2018 ◽  
Vol 4 (1) ◽  
pp. 47
Author(s):  
Indah Naryati
Keyword(s):  
Degrees Of Freedom ◽  
Formative Evaluation ◽  
Cognitive Learning ◽  
T Test ◽  
P Value ◽  
Group Comparison ◽  
Guided Inquiry ◽  
Teaching Materials ◽  
Significant Difference ◽  
Static Group

ABSTRAKLembar Kegiatan Siswa (LKS) adalah salah satu bagian dari bahan ajar. Sebagai salah satu bagian dari bahan ajar, LKS merupakan komponen yang penting dalam pembelajaran. Berdasarkan hasil penelitian pendahuluan, LKS yang digunakan masih belum mengarah pada pola pembelajaran yang mengeksplorasi pengetahuan siswa. Penelitian ini bertujuan untuk menghasilkan LKS hasil pengembangan berbasis inkuiri terbimbing pada materi teks diskusi siswa SMP kelas IX yang valid dan efektif. Jenis penelitian ini merupakan penelitian dan pengembangan, kolaborasi model Borg & Gall dan Dick & Carey. Metode yang digunakan adalah kuasi eksperimen (static group comparison design). Sampel penelitian adalah siswa SMP kelas IX, 30 siswa sebagai kelas pembanding, 33 siswa sebagai kelas eksperimen. Alat ukur berupa tes pilihan ganda pada evaluasi formatif sebagai posttest. Analisis data digunakan uji-t untuk sampel berpasangan pada taraf signifikan 5 % (p<0,05). Hasil penelitian menunjukkan LKS tergolong valid berdasarkan rata-rata penilaian pakar sebesar 74,7% dengan kategori cukup valid. Efektif berdasarkan 1) hasil belajar kognitif, rata-rata kelas 90,42 dan melebihi batas ketuntasan (KKM) yang ditetapkan yaitu 80. Hasil uji-t diperoleh nilai t = -9,574 dengan derajat kebebasan (dk) sebesar 61.  Sedangkan p-value (2-tailed)= 0,0000, karena p-value = 0,0000 lebih kecil dari α = 0,05 maka H0 : µ1 = µ2 ditolak, sehingga dapat disimpulkan bahwa ada perbedaan yang signifikan antara posttest kelompok eksperimen dengan kelompok pembanding. Kata Kunci: LKS, inkuiri terbimbing, materi tek diskusi.ABSTRACTStudent Activity Sheet (LKS) is one part of teaching materials. As one part of teaching materials, LKS is an important component in learning. Based on preliminary research results, LKS used still not lead to learning patterns that explore students' knowledge. This study aims to produce LKS based on guided inquiry based on the discussion material of students of SMP class IX class that is valid and effective. This type of research is a research and development, collaboration models Borg & Gall and Dick & Carey. The method used is quasi experiment (static group comparison design). The sample of the research is the students of SMP class IX, 30 students as the comparison class, 33 students as the experimental class. Measurers are multiple choice tests on formative evaluation as posttest. Data analysis used t-test for paired samples at 5% significant level (p <0,05). The result of the research shows that LKS is valid based on the average expert rating of 74.7% with the category is quite valid. Effective on the basis of 1) cognitive learning outcomes, grade averages 90.42 and beyond the defined limit of (KKM) which is defined as 80. T-test results obtained t value = -9.574 with degrees of freedom (dk) of 61. While p-value (2-tailed) = 0,0000, since p-value = 0,0000 is smaller than α = 0.05 then H0: μ1 = μ2 is rejected, so it can be concluded that there is a significant difference between the experimental group posttest and the comparison group. Keywords: LKS, guided inquiry, discussion material.

scholarly journals Conditional teleportation of quantum-dot spin states

2020 ◽  
Vol 11 (1) ◽  
Author(s):  
Haifeng Qiao ◽  
Yadav P. Kandel ◽  
Sreenath K. Manikandan ◽  
Andrew N. Jordan ◽  
Saeed Fallahi ◽  
...  
Keyword(s):  
Quantum Dot ◽  
Spin States

scholarly journals Spin-momentum entanglement in a Bose–Einstein condensate

2020 ◽  
Vol 22 (44) ◽  
pp. 25669-25674
Author(s):  
Sumit Suresh Kale ◽  
Yijue Ding ◽  
Yong P. Chen ◽  
Bretislav Friedrich ◽  
Sabre Kais
Keyword(s):  
Degrees Of Freedom ◽  
Raman Laser ◽  
Einstein Condensate ◽  
Spin States ◽  
Field Coupling ◽  
Bose Einstein Condensate ◽  
Bose Einstein ◽  
Spin Momentum

Mechanisms including two types of Raman laser coupling (Ω1 & Ω2) and rf field coupling (Ωrf) are applied to drive transitions between different hyperfine spin states. We investigated the entanglement between the spin and momentum degrees of freedom.

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