Home.

Here is A0 again, followed by the six possibilities when one of its qubits is p-measured:

Qureg A0
StateAmplitudeProbability
│000 ⟩+0.32272 − 0.12294i0.11926
│001 ⟩−0.16136 + 0.03074i0.02698
│010 ⟩−0.17673 − 0.19210i0.06813
│011 ⟩+0.25645 + 0.11105i0.07810
│100 ⟩+0.07684 + 0.39188i0.15947
│101 ⟩+0.22712 − 0.18991i0.08765
│110 ⟩+0.57598 − 0.25131i0.39490
│111 ⟩+0.23749 + 0.09535i0.06549
naïve = 0.66390

p-measuring the first bit gives one of these:

Qureg A6
StateAmplitudeProbability
│000 ⟩+0.59673 − 0.22733i0.40777
│001 ⟩−0.29837 + 0.05683i0.09225
│010 ⟩−0.32678 − 0.35520i0.23295
│011 ⟩+0.47419 + 0.20534i0.26702
│100 ⟩00
│101 ⟩00
│110 ⟩00
│111 ⟩00
naïve = 0.31688
Qureg A7
StateAmplitudeProbability
│000 ⟩00
│001 ⟩00
│010 ⟩00
│011 ⟩00
│100 ⟩+0.09135 + 0.46589i0.22539
│101 ⟩+0.27002 − 0.22578i0.12389
│110 ⟩+0.68476 − 0.29877i0.55815
│111 ⟩+0.28234 + 0.11336i0.09257
naïve = 0.57119

p-measuring the second bit gives one of these:

Qureg A8
StateAmplitudeProbability
│000 ⟩+0.51455 − 0.19602i0.30319
│001 ⟩−0.25728 + 0.04900i0.06859
│010 ⟩00
│011 ⟩00
│100 ⟩+0.12251 + 0.62481i0.40540
│101 ⟩+0.36213 − 0.30280i0.22282
│110 ⟩00
│111 ⟩00
naïve = 0.28620
Qureg A9
StateAmplitudeProbability
│000 ⟩00
│001 ⟩00
│010 ⟩−0.22691 − 0.24664i0.11232
│011 ⟩+0.32926 + 0.14258i0.12874
│100 ⟩00
│101 ⟩00
│110 ⟩+0.73951 − 0.32266i0.65098
│111 ⟩+0.30492 + 0.12242i0.10796
naïve = 0.48651

p-measuring the third bit gives one of these:

Qureg A10
StateAmplitudeProbability
│000 ⟩+0.37471 − 0.14275i0.16078
│001 ⟩00
│010 ⟩−0.20520 − 0.22304i0.09185
│011 ⟩00
│100 ⟩+0.08922 + 0.45500i0.21499
│101 ⟩00
│110 ⟩+0.66876 − 0.29179i0.53238
│111 ⟩00
naïve = 0.21997
Qureg A11
StateAmplitudeProbability
│000 ⟩00
│001 ⟩−0.31754 + 0.06048i0.10449
│010 ⟩00
│011 ⟩+0.50466 + 0.21853i0.30244
│100 ⟩00
│101 ⟩+0.44695 − 0.37373i0.33944
│110 ⟩00
│111 ⟩+0.46736 + 0.18764i0.25363
naïve = 0.66578

Entanglement can increase when bits are p-measured, because nonvanishing amplitudes are scaled up to restore the total probability to unity.